Digital Ground Resistance Tester Model 4500
11
3.3
Table of Influencing Parameters
Supply Voltage
Temperature
Auxiliary
Electrode
Resistance (Ry)
Influence of
Auxiliary
Electrode
Resistance (Rz)
in Relation to
Test Current
DC Voltage in
Series with Rx
AC 60 Hz Stray
Voltage Influence
in Series with
Rx, Ry or Rz
Reference
Conditions
12V ±0.2V
11 to 14V DC
73˚F ±37˚F
23˚F to 122˚F
23˚C ±3˚C
-5˚C to 50˚C
±0.5% /50˚F
(3)
±0.5% /10˚C
0.2% /volt
0.3% /volt
±1% /50˚F
(3)
Ry = 0
0 to 50k
Ω
(1)
N/A
N/A
See Table 3
N/A
0 to 20V DC
(2)
Rz = 0
See Table 3
0.5% /10k
Ω
(1)
2mA: 0.1%/10k
Ω
10mA: 0.1%/3k
Ω
50mA: 0.1%/1k
Ω
2mA: 0.3%/10k
Ω
10mA: 0.3%/3k
Ω
50mA: 0.3%/1k
Ω
or 5 cts
1% /10k
Ω
(1)
±1% /10˚C
Operating
Conditions
% of Measurement
Typical
Maximum
Parameters
Table 1
1. For the 2
Ω
range (2mA and 10mA test currents), maximum Ry is
5k
Ω
. Influence will typically be 0.5%/5k
Ω
, with a maximum of 1%
max/5k
Ω
or 3cts.
2. Presence of DC voltage may tend to limit the maximum (Rx + Rz)
level indicated within Table 3.
3. From 10% to 100% of measuring scale interval. It is necessary to add
the following quantities to those indicated with Table 1:
± 10m
Ω
for 2
Ω
/2mA range
± 3m
Ω
for 2
Ω
/10mA range
± 1 count for other ranges
