752A Reference Divider Data Sheet Brochure
User Manual: 752A-Reference-Divider-Data-Sheet-Brochure
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Features of the Fluke Calibration 752A
• 10:1 and 100:1 divider outputs
• Output uncertainty 0.2 ppm and 0.5 ppm
• Built-in Calibration Bridge
• Dynamic Resistor Matching™
• System switching for ease of use
The Fluke Calibration 752A Reference Divider
sets the standard for ratio accuracy and ease of
use. It offers two divider outputs, 10:1 and 100:1
with output uncertainties of less than 0.2 ppm
and 0.5 ppm respectively.
Before each use, the 752A is easily calibrated
with only a stable source and a null detector.
The entire procedure takes only ﬁve minutes
and does not require external standards.
The calibration procedure compensates for
long term changes in value of the divider resis-
tors. The upper leg of the divider is conﬁgured
into three equal groups, which, when placed
in parallel, form a resistor of equal value to the
output resistor. These two resistors form one
half of a Wheatstone bridge. The other half is
composed of two calibration resistors whose
positions can be interchanged in the circuit.
This interchange allows correction for any dif-
ference in the values of the calibration resistors
through use of the BALANCE knob on the front
panel. The upper leg resistors are then matched
to the output resistor with the 10:1 or 100:1
In the stand-alone divider mode, input to the
divider is applied to the INPUT terminals and is
switched by the MODE switch to either the 10:1
or the 100:1 position. Output from the divider is
then available at the OUTPUT terminals.
When the 752A is augmented with a 10 V
reference source (such as the Fluke Calibration
732B) and a null detector, the resulting system
becomes the 5-decade cardinal point voltage
calibrator with facilities for comparing input
voltages of 1000 V, 100 V, 10 V, 1 V and 0.1 V
to the 10 V reference. In this mode, the voltage
source to be calibrated is connected to the 752A
input terminals and the MODE switch reconﬁg-
ures the system for each of the ranges with no
manual lead changing necessary.
When the MODE switch is turned to the 752
CAL position, the 752A divider resistors are
switched to form a bridge circuit with the two
additional calibration resistors. Bridge excitation
is supplied from the voltage source (set for an
output of 20 V) connected to the input terminals
and the null detector is switched across the
bridge to measure bridge balance.
Bridge balance control
Divider calibration controls
Input from voltage source
Output to null detector
Input from reference standard
(if 10V then MODE switch
valid for input values)
Calibrate switch inverts
MODE switch selects
Output from divider for
2 Fluke Calibration 752A Reference Divider Speciﬁcations
These speciﬁcations apply for the lifetime of the
instrument over the temperature range of 18 °C
to 28 °C.
The Fluke Calibration 752A may be calibrated
and operated in the normal temperature range
of 18 °C to 28 °C. The following table describes
the ratio uncertainty of the 752A that applies for
a temperature variation of less than ± 1 °C from
the calibration temperature for up to eight hours
Temperature coefﬁcient of ratio
Temperature coefﬁcient of ratio is < ± 1 ppm/°C
over the entire operating range. Typical perfor-
mance from 15 °C to 30 °C is 0.1 ppm/°C.
10:1 ratio: 380 kΩ ± 1 %
100:1 ratio: Divider 4 MΩ
Driver Guard 4 MΩ
Total 2 MΩ ± 1 %
Maximum input voltage
10:1 ratio: 200 V. This speciﬁcation applies to
the safety of the unit only. The maximum volt-
age for best accuracy is 100 V.
100:1 range: 110 0 V
Power coefﬁcient effect on ratio
10:1 ratio: < 0.05 ppm of output with 100 V
100:1 ratio: < 0.3 ppm of output with 1000 V
Note: These speciﬁcations are already included in the Ratio
Net: 8.4 kg (18.5 lb)
Shipping: 13.6 kg (30 lb)
Size: 60.3 cm L x 22.1 cm W x 19.1 cm H
(23.75 in L x 8.69 in W x 7.53 in H)
Compliance with standards
ANSI C39.5, 1980. IEC 348, 2nd edition, 1978
Temperature and humidity
Condition Temperature % Relative Humidity
Non-operating -40 °C to +75 °C
0 °C to 50 °C
95 ± 5 % max.
Operating 0 °C to 40 °C
40 °C to 50 °C
75 ± 5 % max.
45 ± 5 % max.
Non-operating: 0 to 12,000 m (40,000 ft)
Operating: 0 to 3,050 m (10,000 ft)
Per MIL-T-288800C, Type III, Class 5, Style E
Options and accessories
M07-200-603 Full Width Rack Mount Kit
The Full Width Rack Mount Kit permits the 752A
to be rack mounted side-by-side with another
half rack width instrument, such as the 732A
DC Reference Standard. This rack mounting
method requires the 752A to be bolted to the
adjacent instrument using four M00-800-523
Dual Mounting Fasteners, which are included
with the kit. Assembly instructions are supplied
with the kit.
5440A-7002 Low Thermal EMF Cables
The Low Thermal EMF Cables are a set of three
shielded, 2-conductor cables terminated with
beryllium copper low thermal EMF banana plug
connectors. One cable is four feet long and two
are two feet long. The cables are particularly
well suited for interconnecting a 752A, 732B
and a null detector for calibration of a 5700
Series Direct Voltage Calibrator. In addition,
they will be found useful for general purpose
lab work where the low thermal EMF and quick
disconnect features are important.
752A Reference Divider
M07-200-603 7-inch Full Width Dual Rack
5440A-7002 Low Thermal EMF Cable Assembly
Range Input Voltage
10:1 100 V 0.2 ppm ± 0.5 µV
100:1 1000 V 0.5 ppm ± 1.0 µV
*Null uncertainty refers to the required uncertainty of the null detector
reading during calibration.
PO Box 9090, Everett, WA 98206 U.S.A.
Fluke Europe B.V.
PO Box 1186, 5602 BD
Eindhoven, The Netherlands
Web access: http://www.flukecal.eu
Fluke Calibration. Precision, performance, confidence.™
For more information call:
In the U.S.A. (877) 355-3225 or
Fax (425) 446-5116
In Europe/M-East/Africa +31 (0) 40 2675 200 or
Fax +31 (0) 40 2675 222
In Canada (800)-36-FLUKE or
Fax (905) 890-6866
From other countries +1 (425) 446-5500 or
Fax +1 (425) 446-5116
Web access: http://www.flukecal.com
©2008-2014 Fluke Calibration.
Speciﬁcations subject to change without notice.
Printed in U.S.A. 1/2014 1268770E_EN
Modification of this document is not
permitted without written permission
from Fluke Calibration.