2
RS-925D
2
Specifications
Chapter 2
SpECIfICaTIOnS
For convenience to the user, the pertinent specifications are given in a typical
OPERATING GUIDE
, like the
one shown in Figure 2.1, affixed to the case of the instrument.
SpECIfICaTIOnS
Resistance
per step
Total
decade
resistance
Max
current
Max
power
Temperature
coefficient
(±ppm/ºC)
Power
coefficient
(±ppm/mW)
Accuracy*
Stability
(±ppm/yr)
Decade positions
Resistor type
whichever applies first
100 µΩ/division
20 μΩ resolution
10 mΩ
2 A
NA
20
1
Continuous
Rheostat
10 mΩ
100 mΩ
2 A
NA
20
1
±(20 ppm+0.5 m
Ω
)
20 ppm+0.5 m
Ω
10 positions "1"-"10"
(10 mΩ minimum reading)
resistance wire
100 mΩ
1 Ω
2 A
NA
20
1
11 positions "0"-"10"
(12 positions "0"-"11" for
highest decade)
1 Ω
10 Ω
1 A
5 W
20
0.4
Wirewound
hermetically sealed
low-inductance
10 Ω
100 Ω
0.33 A
5 W
10
0.3
100 Ω
1 kΩ
0.1 A
5 W
3
0.1
1 kΩ
10 kΩ
33 mA
5 W
3
0.1
10 ppm
(<5 ppm typical)
10 kΩ
100 kΩ
10 mA
5 W
3
0.1
100 kΩ
1 MΩ
3 mA
2,000 V peak
3
0.1
Wiring and switch resistance
NA
50 µΩ/ºC
0.2 µΩ/W
NA
*At 23°C “true ohm” measurement, 30-70% RH, absolute reading, SI traceable
No zero subtraction required
Minimum resistance:
10 mΩ ± 0.5 mΩ; determined by the lowest settable
position, “1”, of the 10 mΩ/step decade
Resistance repeatability:
Better than 100 µΩ, short-term, average value
Leakage Resistance:
>10 GΩ
Environmental Conditions:
Operating Temperature:
0ºC to 55ºC
Storage Temperature:
-40ºC to 70ºC
Switch Type:
Multiple solid silver contacts; dust-tight diallyl-
phthalate body.
To allow continuous rotation, a blank position is
added on most decades.
Terminals
Four, 5-way, gold-plated, tellurium-copper binding
posts with low thermal emf and low resistance,
for four-terminal Kelvin measurements, plus one
binding post connected to case for shielding. Rear
outputs are available as an option.
Mechanical Information:
Model
Dimensions
Weight
8 decades
48.3 cm W x 17.8 cm H x 19.7 cm d
(19" W x 7" H x 7.8" d)
5.1 kg
(11 lb)
