Manual

User Manual:

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Page Count: 27

Unified measurement

software

UMS

Reference manual

Version: 2.19

DOI: 10.3929/ethz-b-000247100

Reto Pfenninger, Eva Sediva, Sören

Boyn, Jennifer L.M. Rupp

D-MATL, ETH Zürich

Table of Content

List of devices supported by UMS: ................................................................................................................ 3

Function reference: .......................................................................................................................................... 4

Preforming of memristors .............................................................................................................................. 4

Cyclic voltammetry ........................................................................................................................................ 7

Pulsed experiments ..................................................................................................................................... 12

Simple loggers ............................................................................................................................................. 17

Oven control programs ................................................................................................................................ 20

Impedance measurement ............................................................................................................................ 23

Mass flow controller ..................................................................................................................................... 24

Galvanostatic cycling ................................................................................................................................... 25

High precision galvanostatic cycling ........................................................................................................... 26

List of devices supported by UMS:

The unified measurement software currently supports the devices listed below. Please keep in mind that the

functionality was adapted to our needs so there might be functionalities which are not yet implemented in a

specific device.

Keithley measurement devices:

 Keithley 740

 Keithley 2000

 Keithley 2001

 Keithley 2182A

 Keithley 2601B

 Keithley 2602B

 Keithley 2612B

 Keithley 2700

 Keithley 2701

 Keithley 6517B

 Keithley 7001

 Keithley 6220

 Keithley 4200 SCS

Tektronix devices:

 Tektronix AFG2021

 Tektronix AFG3021C

Power supplies:

 TTI QL564TP

Impedance bridges:

 Gamry Reference 600

 Zahner IM6

 Solartron 1260

Oven controllers:

 Eurotherm 2404

 Eurotherm 2416

 Eurotherm 3216

 Eurotherm 3500

 Eurotherm nanodac

GPIB Adapters:

 Prologix GPIB-USB Adapter

 Prologix GPIB-Ethernet Adapter

Function reference:

General remarks:

 If not stated otherwise, all function arguments are in SI units.

 Arguments, which already have a default value, do not need to be specified if you want to keep them

at the default value.

 Before passing the device to a function, make sure you initailized it.

 Code examples are set in this particular font

Preforming of memristors

preforming_ramp(device,start_voltage,ramp_speed_1,top_voltage,hold_time,ramp_spe

ed_2,end_voltage,compliance_current=0,new_row=False, GUI=True)

Return value are the following arrays: [data_V_I,data_V_t,data_I_t]

This function is used to preform memristors before they are cycled.

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date only

keithley_2601B, keithley_2602B and keithley_2612B and

keithley_6517B can be used. Keep in mind that keithley_6517B

has no compliance current capability.

start_voltage

Where you want to start

ramp_speed_1

V/s

top_voltage

hold_time

You can also set this to 0. Then it does not wait

ramp_speed_2

V/s

Needs to be negative

end_voltage

You can also set this voltage equal to bottom_voltage. Then you

only cycle in the positive branch

compliance_current

CC (Default=0 means no CC is applied)

new_row

Default:

False

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Default:

True

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

preforming_ramp_with_current_limit(device,start_voltage,ramp_speed_1,top_voltage

,hold_time,ramp_speed_2,end_voltage,stop_current,new_row=False, GUI=True)

Return value are the following arrays: [data_V_I,data_V_t,data_I_t]

This function does basically the same as the above one, but was especially designed for the High resistance

meter Keithley 6517B which does not support compliance currents. Therefore we replaced it by a certain

„stop_current“.

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date only

keithley_2601B, keithley_2602B and keithley_2612B and

keithley_6517B can be used. Keep in mind that keithley_6517B

has no compliance current capability.

start_voltage

Where you want to start

ramp_speed_1

V/s

top_voltage

hold_time

You can also set this to 0. Then it does not wait

ramp_speed_2

V/s

Needs to be negative

end_voltage

You can also set this voltage equal to bottom_voltage. Then you

only cycle in the positive branch

stop_current

If this specific current value is reached, the function immediately

stops and no further voltage is applied.

new_row

Default:

False

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Default:

True

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

preforming_ramp_with_current_hold_time(device,start_voltage,ramp_speed_1,top_vol

tage,hold_time,ramp_speed_2,end_voltage,compliance_current=0,trigger_current=0,t

rigger_hold_time=0,new_row=False,GUI=True)

Return value are the following arrays: [data_V_I,data_V_t,data_I_t]

This function does a usual preforming as the preformin_ramp function with the additional possibility to add a

certain trigger_current after which the function only runs for the amount of time specified in trigger_hold_time

and then stops immediately even if the hold_time is set for some longer time.

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date only

keithley_2601B, keithley_2602B and keithley_2612B and

keithley_6517B can be used. Keep in mind that keithley_6517B

has no compliance current capability.

start_voltage

Where you want to start

ramp_speed_1

V/s

top_voltage

hold_time

You can also set this to 0. Then it does not wait. In this case it

does not make sense to set this value low since you usually

want the current to rise over time till trigger_current is reached.

ramp_speed_2

V/s

Needs to be negative

end_voltage

You can also set this voltage equal to bottom_voltage. Then you

only cycle in the positive branch

compliance_current

CC (Default=0 means no CC is applied)

trigger_current

(Default=0 means deactivated) After the here specified current

has been reached (can be at any time), a second counter starts

to run which will wait for trigger_hold_time seconds to stop the

whole function

trigger_hold_time

(Default=0 means sudden stop after trigger_current has been

reached). This variable states how many seconds the function

should run more after trigger_current has been reached.

new_row

Default:

False

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Default:

True

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

Cyclic voltammetry

cycling(device,start_voltage,ramp_speed_1,top_voltage,top_hold_time,ramp_speed_2

,bottom_voltage,bottom_hold_time,end_voltage,n,compliance_current_pos=0,complian

ce_current_neg=0,new_row=False, GUI=True)

Return value are the following arrays: [data_V_I,data_V_t,data_I_t]

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date only

keithley_2601B, keithley_2602B and keithley_2612B and

keithley_6517B can be used. Keep in mind that keithley_6517B

has no compliance current capability.

start_voltage

Where you want to start

ramp_speed_1

V/s

top_voltage

top_hold_time

You can also set this to 0. Then it does not wait

ramp_speed_2

V/s

Needs to be negative

bottom_voltage

You can also set this voltage equal to end_voltage. Then you

only cycle in the positive branch

bottom_hold_time

You can also set this to 0. Then it does not wait

end_voltage

You can also set this voltage equal to bottom_voltage. Then you

only cycle in the positive branch

Number of cycles you want to run

compliance_current_pos

CC in positive branch. Needs to be positive

compliance_current_neg

CC in negative branch. Needs to be positive

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

cycling_two_channels(device,start_voltage_1,start_voltage_2,ramp_speed_1_1,ramp_

speed_1_2,top_voltage_1,top_voltage_2,top_hold_time_1,top_hold_time_2,ramp_speed

_2_1,ramp_speed_2_2,bottom_voltage_1,bottom_voltage_2,bottom_hold_time_1,bottom_

hold_time_2,end_voltage_1,end_voltage_2,n_1,n_2,compliance_current_pos_1=0,compl

iance_current_pos_2=0,compliance_current_neg_1=0,compliance_current_neg_2=0,new_

row=False,GUI=True)

Return value are the following arrays:

[data_V_I_1,data_V_t_1,data_I_t_1,data_V_I_2,data_V_t_2,data_I_t_2]

Blue is for Channel A and Green for Channel B

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date only

keithley_2602B and keithley_2612B can be used.

start_voltage_1

Where you want to start

ramp_speed_1_1

V/s

top_voltage_1

top_hold_time_1

You can also set this to 0. Then it does not wait

ramp_speed_2_1

V/s

Needs to be negative

bottom_voltage_1

You can also set this voltage equal to end_voltage. Then you

only cycle in the positive branch

bottom_hold_time_1

You can also set this to 0. Then it does not wait

end_voltage_1

You can also set this voltage equal to bottom_voltage. Then

you only cycle in the positive branch

n_1

Number of cycles you want to run

compliance_current_pos_1

CC in positive branch. Needs to be positive

compliance_current_neg_1

CC in negative branch. Needs to be positive

start_voltage_2

Where you want to start

ramp_speed_1_2

V/s

top_voltage_2

top_hold_time_2

You can also set this to 0. Then it does not wait

ramp_speed_2_2

V/s

Needs to be negative

bottom_voltage_2

You can also set this voltage equal to end_voltage. Then you

only cycle in the positive branch

bottom_hold_time_2

You can also set this to 0. Then it does not wait

end_voltage_2

You can also set this voltage equal to bottom_voltage. Then

you only cycle in the positive branch

n_2

Number of cycles you want to run

compliance_current_pos_2

CC in positive branch. Needs to be positive

compliance_current_neg_2

CC in negative branch. Needs to be positive

new_row

Either True or False If set to True, the plotting window will

make a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will

not appear at all. Can be used for „silent“ measurements

without real-time graphical output.

cycling_unipolar(device,start_voltage,ramp_speed_1,set_voltage,set_hold_time,com

pliance_current,ramp_speed_2,wait_before_reset_time,reset_voltage,reset_ramp_rat

e,reset_hold_time,n,new_row=False, GUI=True)

Return value are the following arrays: [data_V_I,data_V_t,data_I_t]

This function is optimized to test memristors for unipolarity. In normal cycling a compliance current is either

applied globally or not at all. It is therefore possible, that unipolar switching behavior can not be asessed

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date only

keithley_2601B, keithley_2602B and keithley_2612B can be

used.

start_voltage

Where you want to start

ramp_speed_1

V/s

set_voltage

set_hold_time

You can also set this to 0. Then it does not wait

compliance_current

ramp_speed_2

V/s

Needs to be negative

wait_before_reset_time

You can also set this to 0. Then it does not wait

reset_voltage

reset_ramp_rate

V/s

This ramp rate is applied to both. Reset-ramp-up and reset-

ramp-down

reset_hold_time

You can also set this to 0. Then it does not wait

Number of cycles you want to run

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

cycling_current(device,start,ramp_speed_1,top,top_hold_time,ramp_speed_2,bottom,

bottom_hold_time,end,n,maximum_voltage,new_row=False,GUI=True)

Return value are the following arrays: [data_V_I,data_V_t,data_I_t]

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date only

keithley_2601B, keithley_2602B and keithley_2612B can be

used. Keep in mind that keithley_6517B DOES NOT WORK for

this function as it has no compliance current capability.

start

The applied current with which you want to start

ramp_speed_1

A/s

top

The top current you want to reach. (However you have no

influence if your device will be conductive enough to ever

exactly reach that point.)

top_hold_time

You can also set this to 0. Then it does not wait

ramp_speed_2

A/s

Needs to be negative

bottom

You can also set this current equal to end. Then you only cycle

in the positive branch

bottom_hold_time

You can also set this to 0. Then it does not wait

end

You can also set this voltage equal to bottom. Then you only

cycle in the positive branch

Number of cycles you want to run

maximum_voltage

The global maximum voltage you allow the device to apply in

order to reach the beforehand specified ramps. Keep in mind

that the device itself also has some limitations regarding this

variable (mostly ether 40V or 200V depending on the device

used)

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

Pulsed experiments

pulse_rnone(device_smu,device_function_generator,V_peak,const_pulse_width,time_b

etween_pulses, num_pulses,new_row=False,GUI=True)

Return value are the following arrays:

[data_V_t_2,data_I_t_2,data_cycle_R_2,data_cycle_post_R_2]

This function just measures the current responce to a series of voltage pulses - there is no reading voltage

and the currents starts and ends at zero voltage.

Argument

Unit

Remark

device_smu

Pass the device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B,

keithley_6517B can be used.

device_function_generator

Pass the device you want to use for this function. To date

tektronix_AFG2021C and tektronix_AFG3021C can be used.

V_peak

Specifiy the peak voltage you want to be applied to the device.

const_pulse_width

Specify the with of the individual pulses

time_between_pulses

Specify the wait time between different pulses

num_pulses

How many pulses should be applied in total till the function ends

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

pulse_rsquare(device_smu,device_function_generator,V_peak,const_pulse_width,time

_between_pulses, num_pulses,time_at_zero,

V_read,alternate=True,new_row=False,GUI=True)

Return value are the following arrays:

[data_V_t_2,data_I_t_2,data_cycle_R_2,data_cycle_post_R_2]

This function allows you to measure also the resistance during (depending on the time scale) and between

pulses. - that means that there is a square reading scheme between the pulses.

Argument

Unit

Remark

device_smu

Pass the device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B,

keithley_6517B can be used.

device_function_generator

Pass the device you want to use for this function. To date

tektronix_AFG2021C and tektronix_AFG3021C can be used.

V_peak

Specifiy the peak voltage you want to be applied to the device.

const_pulse_width

Specify the with of the individual pulses

time_between_pulses

Specify the wait time between different pulses

num_pulses

How many pulses should be applied in total till the function ends

time_at_zero

How long should the system remain at 0V

V_read

Specify the read voltage

alternate

Default:

True

Either True or False If set to True, every 2nd pulse has opposite

polarity

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

In case you put a negative V_peak voltage into the pulse_rsquare function then the reading voltage becomes

automatically also negative. This is due to voltage spikes occurring when changing voltage polarity.

pulse_rbipolar(device_smu,device_function_generator,V_peak,const_pulse_width,tim

e_between_pulses, num_pulses,time_at_zero, V_read, alternate=True,

new_row=False,GUI=True)

Return value are the following arrays:

[data_V_t_2,data_I_t_2,data_cycle_R_2,data_cycle_post_R_2_plus,

data_cycle_post_R_2_minus]

This function allows you to measure also the resistance during (depending on the time scale) and between

pulses. There is a bipolar pulse reading scheme between the pulses. This is an advantage over a constant

reading scheme since the device will not be disturbed. No resistence will be measured during the time at zero.

This is just an option to leave the current to equilibrate.

Argument

Unit

Remark

device_smu

Pass the device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B,

keithley_6517B can be used.

device_function_generator

Pass the device you want to use for this function. To date

tektronix_AFG2021C and tektronix_AFG3021C can be used.

V_peak

Specifiy the peak voltage you want to be applied to the device.

const_pulse_width

Specify the with of the individual pulses

time_between_pulses

Specify the wait time between different pulses

num_pulses

How many pulses should be applied in total till the function ends

time_at_zero

How long should the system remain at 0V

V_read

Specify the read voltage

alternate

Default:

True

Either True or False If set to True, every 2nd pulse has opposite

polarity

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

The bipolar read between the pulses ensures that no memristance change occurs during the reading process

(a change during a positive reading pulse will be reversed with a negative reading pulse). Is a good choice for

sensitive devices or higher reading voltages.

Simple loggers

Those functions are kept very simple for the case one just needs to monitor some measurement without

further requirements.

voltage_logger(device,total_measurement_time,bias_current=0,new_row=False,

GUI=True)

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B,

keithley_6517B, keithley_2000, keithley_2001, keithley_2700,

keithley_2182A can be used.

total_measurement_time

How long you want to log the voltage

bias_current

Specifiy the bias current you want to be applied to the device.

Default = 0 means no bias at all

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

current_logger(device,total_measurement_time,bias_voltage=0,new_row=False,

GUI=True)

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B,

keithley_6517B, keithley_2000, keithley_2001, keithley_2700,

keithley_2182A can be used.

total_measurement_time

How long you want to log the voltage

bias_voltage

Specifiy the bias voltage you want to be applied to the device.

Default = 0 means no bias at all

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

resistance_2w_logger(device,total_measurement_time,new_row=False, GUI=True)

Measures resistance with 2-wire setup

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B,

keithley_6517B, keithley_2000, keithley_2001, keithley_2700,

keithley_2182A can be used.

total_measurement_time

How long you want to log the voltage

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

resistance_4w_logger(device,total_measurement_time,new_row=False, GUI=True)

Measures resistance with 4-wire setup

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B,

keithley_6517B, keithley_2000, keithley_2001, keithley_2700,

keithley_2182A can be used.

total_measurement_time

How long you want to log the voltage

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

temperature_logger(device,total_measurement_time,sensor=“K“,num_of_channels=1,ne

w_row=False, GUI=True)

Argument

Unit

Remark

device

Pass the device you want to use for this function. To date

keithley_2000, keithley_2001, keithley_2700, keithley_2182A

can be used.

total_measurement_time

How long you want to log the voltage

sensor

Default:

Specify which type of thermocouple you will be using. Choose

from J,T,S,E,R,B,N,K

num_of_channels

Default:

Which channels do you want to use. (Not working at the

moment)

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

temperature_current_logger(device_temperature,device_smu,total_measurement_time,

bias_voltage,sensor=“K“,new_row=False, GUI=True)

Argument

Unit

Remark

device_temperature

Pass the device you want to use for this function. To date

keithley_2000, keithley_2001, keithley_2700, keithley_2182A

can be used.

device_smu

Pass the SMU device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B,

keithley_6517B can be used.

total_measurement_time

How long you want to log the voltage

bias_voltage

Put the voltage value the SMU should source during the

experiment.

sensor

Default:

Specify which type of thermocouple you will be using. Choose

from J,T,S,E,R,B,N,K

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

Oven control programs

sintering(device_temperature,device_oven,temperature_values,ramp_rate,stabilizat

ion_time,sensor=“K“,GUI=True)

Argument

Unit

Remark

device_temperature

Pass the device you want to use for this function. To

date keithley_2601B, keithley_2612B,

keithley_6517B, keithley_2000, keithley_2001,

keithley_2700, keithley_2182A can be used.

device_oven

Pass the oven device you want to use for this

function. To date eurotherm_2404, eurotherm_2416,

eurotherm_3216 can be used.

temperature_values

°C

Can be a single value like 850 or an array of values

like [200,400,600,800]. Then those values are all run

to with the ramp_rate specified and hold for as long

as stabilization_time

ramp_rates

K/min

NOT SI unit

Set the ramp rate(s). Can be a single number or an

array like [300,400,500]

stabilization_times

How long a temperature should be kept after having

ramped to that value.

sensor

Default:

Specify which type of thermocouple you will be using.

Choose from J,T,S,E,R,B,N,K

GUI

Either True or False If set to False, the plotting

window will not appear at all. Can be used for

„silent“ measurements without real-time graphical

output.

arrhenius_dc(device_temperature,device_smu,device_oven,temperature_values,ramp_r

ates,stabilization_times,voltage_values,measurement_time=60,continuous_voltage=T

rue,GUI=True)

Return value are the following arrays: [data_T_t,data_P_t,data_I_t,data_R_T]

Argument

Unit

Remark

device_temperature

Pass the device you want to use for this function. To date

keithley_2000, keithley_2001, keithley_2700, keithley_2182A

can be used.

device_smu

Pass the SMU device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B,

keithley_6517B can be used.

device_oven

Pass the oven device you want to use for this function. To date

eurotherm_2404, eurotherm_2416, eurotherm_3216 can be

used.

temperature_values

°C

Can be a single value like 850 or an array of values like

[200,400,600,800]. Then those values are all run to with the

ramp_rate specified and hold for as long as stabilization_time

ramp_rates

K/min

NOT SI

unit

Set the ramp rate(s). Can be a single number or an array like

[300,400,500]

stabilization_times

How long a temperature should be kept after having ramped to

that value.

voltage_values

[Array] or single number of voltage value(s) you want to apply to

the device at each temperature specified under

temperature_values.

measurement_time

How many seconds you want to perform the actual

measurement per each voltage specified. Default is 60 sec

continuous_voltage

Default:

True

Specify if you want the voltage to be applied during the whole

time (also while ramping) or just after the stabilization for the

time specified in measurement_time. If set to True, the variable

voltage_values cannot be an array but just a single value.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

arrhenius_ac(device_temperature,device_oven,device_impedance,temperature_values,

ramp_rates,stabilization_times,number_of_repetitions=1,start_frequency=0.1,end_f

requency=1.0e6,ac_amplitude=0.1,bias=0,num_points_per_decade=10,path="/home/elec

trochem/lost_data",GUI=True)

There is no return value to this function since the whole data gets already safed to a file specified.

Argument

Unit

Remark

device_temperature

Pass the device you want to use for this function. To date

keithley_2000, keithley_2001, keithley_2700, keithley_2182A

can be used.

device_oven

Pass the oven device you want to use for this function. To date

eurotherm_2404, eurotherm_2416, eurotherm_3216 can be

used.

device_impedance

Pass the impedance bridge device you want to use for this

function. To date Zahner_IM6, Solartron or Gamry Reference

600 can be used.

temperature_values

°C

Can be a single value like 850 or an array of values like

[200,400,600,800]. Then those values are all run to with the

ramp_rate specified and hold for as long as stabilization_time

ramp_rates

K/min

NOT SI

unit

Set the ramp rate(s). Can be a single number or an array like

[300,400,500]

stabilization_times

How long a temperature should be kept after having ramped to

that value.

number_of_repetitions

Specify how many times the impedance measurement should

be repeated to get better signal to noise. Default=1. This

variable should not be changed at the moment since it

produces unexpected result and does not work with all the

impedance bridges so far! You have been warned!

start_frequency

Specify the lower frequency boundary at which your device

should be measured. Default is 0.1 Hz. However the

measurement not always starts at this frequency. This depends

on the impedance bridge.

end_frequency

Specify the higher frequency boundary at which your device

should be measured. Default is 1 MHz. However the

measurement not always starts at this frequency. This depends

on the impedance bridge. Much higher frequency usually don't

make sense and you start measuring your not propperly setup

cables.

ac_amplitude

Specify the voltage amplitude with which you want to excite your

system. The higher the less noise but the more you also affect

and change the system by measuring it. Default is 0.1V

bias

Specify a bias voltage during impedance measurement to better

separate electrode contributions. Default is no bias

num_points_per_decade

How many datapoints should be measured on your final

logarithmic impedance plot. Default is 10 and mostly sufficient to

fit the data.

path

Filepath

Specify a path to which you have write-access where the

datafiles from the different spectra should be safed to. It is

suggested to make a new folder somewhere in the umdata path.

Default is /home/electrochem/lost_data

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

Impedance measurement

impedance(device_impedance, start_frequency, end_frequency, ac_amplitude=0.05,

bias=0, num_points_per_decade=10, new_row=False, GUI=True)

Return value are the following arrays:

[data_Zi_Zr,data_freq_mod,data_bias_ampl_time_range_err_temp]

Argument

Unit

Remark

device_impedance

Pass the impedance bridge device you want to use for this

function. To date Zahner_IM6, Solartron or Gamry Reference

600 can be used.

start_frequency

Specify the lower frequency boundary at which your device

should be measured. Default is 0.1 Hz. However the

measurement not always starts at this frequency. This depends

on the impedance bridge.

end_frequency

Specify the higher frequency boundary at which your device

should be measured. Default is 1 MHz. However the

measurement not always starts at this frequency. This depends

on the impedance bridge. Much higher frequency usually don't

make sense and you start measuring your not propperly setup

cables.

ac_amplitude

Specify the voltage amplitude with which you want to excite your

system. The higher the less noise but the more you also affect

and change the system by measuring it. Default is 0.1V

bias

Specify a bias voltage during impedance measurement to better

separate electrode contributions. Default is no bias

num_points_per_decade

How many datapoints should be measured on your final

logarithmic impedance plot. Default is 10 and mostly sufficient to

fit the data.

new_row

Either True or False If set to True, the plotting window will make

a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will not

appear at all. Can be used for „silent“ measurements without

real-time graphical output.

Mass flow controller

mfc(device_mfc,stabilization_times,flow_rates,GUI=True)

Return value are the following arrays: [data_F_t,data_FP_t]

Pass the following device to this function as an example:

voegtlin_gsc = voegtlin_gsc("/dev/ttyUSB0",[12,3])

The first argument "/dev/ttyUSB0" is the corresponding USB port on that Linux-machine, and the array [12,3]

specifies that the Modbus-Addresses 12 and 3 are used by the devices we want to communicate with.

Argument

Unit

Remark

device_mfc

Pass the mass flow controller device you

want to use for this function. To date only

voegtlin_gsc can be used.

stabilization_times

Specify the time a certain flow should be

kept in each step. You can either use a

scalar if you only have one stabilization

time or an array if you have multiple.

flow_rates

[ string or modbus-address,

sccm ]

Specify for each stabilization step, which

flowmeters should have which set-flow. Use

a 3d-array for multiple flowmeters at

multiple steps. See below for more

information.

GUI

Either True or False If set to False, the

plotting window will not appear at all. Can

be used for „silent“ measurements without

real-time graphical output.

flow_rates example:

You can specify this array in 3 different ways.

It can be in the following manner

[ [ [ "gastype1" or modbusnumber , set_flow ],[...] ] , [...] ]

for example: [[["Air 5000",1000],["N2 300",50]],[["Air 5000",500],["N2 300",150]]]

Assuming you have two stabilization times, this will set Air-flow to 1000 sccm and N2 to 50 sccm in the first

step and Air-flow to 500 sccm and N2 to 150 sccm in the second step.

or if only one gas used:

[ [ "gastype1" or modbusnumber , set_flow ] , [...] ]

for example: [["Air 5000",1000],["Air 5000",700],["Air 5000",100]]

Assuming you have 3 stabilization times, this will set Air-flow to 1000 sccm in the first step to 700 sccm in the

second step and finally to 100 in the 3rd step.

or if only one gas and one flow used:

[ "gastype1" or modbusnumber , set_flow ]

for example: ["Air 5000",1000] In this case during all step 1000sccm Air will be used

Galvanostatic cycling

galvanostatic_cycling(device_smu,current_1,target_voltage_1,hold_time_1,hold_cur

rent_1,current_2,target_voltage_2,hold_time_2,hold_current_2,n=1,ocv_measurement

_time=0,set_I_zero_after_cycle=False,new_row=False,GUI=True)

Return value are the following arrays: [data_0,data_1,data_2,data_3]

Argument

Unit

Remark

device_smu

Pass the device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B can be

used.

current_1

Specify the constant current which should be applied in the

first stage of either charge or discharge. (Note: different

currents can be set for charge and discharge)

target_voltage_1

Specify the voltage to which the cell should be charged or

discharged

hold_time_1

Time to stay at target_voltage_1 after reaching it

hold_current_1

Wait at target_voltage_1 until the current drops to this value or

hold_time_1 is over, whatever condition comes first.

current_2

Specify the constant current which should be applied in the

second stage of either charge or discharge. (Note: different

currents can be set for charge and discharge)

target_voltage_2

Specify the voltage to which the cell should be charged or

discharged

hold_time_2

Time to stay at target_voltage_2 after reaching it

hold_current_2

Wait at target_voltage_2 until the current drops to this value or

hold_time_2 is over, whatever condition comes first.

Number of cycles the cell should be tested for. (Can be an

array for rate capability testing)

ocv_measurement_time

How long the open circuit voltage should be measured prior to

any cycling

Set_I_zero_after_cycle

Disconnects the electrochemical cell galvanically from the

measurement device after the cycle

new_row

Either True or False If set to True, the plotting window will

make a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will

not appear at all. Can be used for „silent“ measurements

without real-time graphical output.

Galvanostatic cycling examples:

You can specify arrays for the purpose of rate capability testing.

galvanostatic_cycling(device_smu,[10e-9,100e-9,10e-9], 4.1,0,0,[-10e-9,-100e-9,-

10e-9], 1.1,0,0,n=[10,5,10], ocv_measurement_time=60)

this example: will perform 10 cycles at 10 nA of current followed by 5 cycles at 100 nA and then go back to 10

cycles at 10 nA. OCV is measured for 1 minute and the cycling range is between 1.1 Volts and 4.1 Volts.

High precision galvanostatic cycling

This function is intended to be used in combination with a high precision current source such as Keithley 6220

series in order to cycle under most stable low currents. Note that the function is similar to the previous

description, but a second device file (the current source) has to be provided in addition. The current source is

exclusively dedicated to providing stable ultra-low currents.

galvanostatic_cycling_nano(device_voltmeter,device_current_source,current_1,targ

et_voltage_1,hold_time_1,hold_current_1,current_2,target_voltage_2,hold_time_2,h

old_current_2,n=1,ocv_measurement_time=0,set_I_zero_after_cycle=False,new_row=Fa

lse,GUI=True)

Return value are the following arrays: [data_0,data_1,data_2,data_3]

Argument

Unit

Remark

device_smu

Pass the device you want to use for this function. To date

keithley_2601B, keithley_2602B, keithley_2612B can be

used.

device_current_source

Pass the device you want to use for ultra-low high precision

current to be sourced. To date only keithley_6220 can be

used.

current_1

Specify the constant current which should be applied in the

first stage of either charge or discharge. (Note: different

currents can be set for charge and discharge)

target_voltage_1

Specify the voltage to which the cell should be charged or

discharged

hold_time_1

Time to stay at target_voltage_1 after reaching it

hold_current_1

Wait at target_voltage_1 until the current drops to this value or

hold_time_1 is over, whatever condition comes first.

current_2

Specify the constant current which should be applied in the

second stage of either charge or discharge. (Note: different

currents can be set for charge and discharge)

target_voltage_2

Specify the voltage to which the cell should be charged or

discharged

hold_time_2

Time to stay at target_voltage_2 after reaching it

hold_current_2

Wait at target_voltage_2 until the current drops to this value or

hold_time_2 is over, whatever condition comes first.

Number of cycles the cell should be tested for. (Can be an

array for rate capability testing)

ocv_measurement_time

How long the open circuit voltage should be measured prior to

any cycling

Set_I_zero_after_cycle

Disconnects the electrochemical cell galvanically from the

measurement device after the cycle

new_row

Either True or False If set to True, the plotting window will

make a new row and the display looks nicer.

GUI

Either True or False If set to False, the plotting window will

not appear at all. Can be used for „silent“ measurements

without real-time graphical output.

Galvanostatic cycling examples:

galvanostatic_cycling_nano(device_smu, device_current_source, 10e-9, 4.2,0,0,-

10e-9, 1.1,0,0,n=100, ocv_measurement_time=120)

this example: will perform 100 cycles at 10 nA of current. OCV is measured for 2 minute and the cycling range

is between 1.1 Volts and 4.2 Volts.

You can specify arrays for the purpose of rate capability testing.

galvanostatic_cycling_nano(device_smu, device_current_source, [10e-9,100e-9,10e-

9], 4.1,0,0,[-10e-9,-100e-9,-10e-9], 1.1,0,0,n=[10,5,10],

ocv_measurement_time=60)

this example: will perform 10 cycles at 10 nA of current followed by 5 cycles at 100 nA and then go back to 10

cycles at 10 nA. OCV is measured for 1 minute and the cycling range is between 1.1 Volts and 4.1 Volts.

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