Calculation of the DD term
Specifi ed range
0.02 ... 50.00
Resolution
Accuracy
± 10% + 1 ct
Capacitance measurement (after discharge of tested element)
Specifi ed measurement range
Resolution
Accuracy
7.3. POWER SUPPLY
The instrument is supplied by:
NiMH rechargeable batteries - 8 x 1.2V / 3.5 Ah
External charging: 85 to 256 V / 50-60 Hz
Minimum battery life (as per IEC 61557-2)
Test voltage
Nominal load
Number of 5-s measurements on
nominal load (with 25-s pauses
between measurements)
Mean battery life
Assuming a 1-minute DAR measurement 10 times a day and a 10-minute PI measurement 5 times a
day, the battery life will be approximately 15 working days, or 3 weeks.
Charging time
6 hours to recover 100% capacity (10 hours if the battery is completely run down).
0.5 hours to recover 10% capacity (battery life approximately 2 days).
Remark: it is possible to charge the batteries while making insulation measurements, provided that the
values measured are greater than 20 M . In that case, the charging time is longer than 6 hours,
and depends on the frequency of the measurements made.
7.4. ENVIRONMENTAL CONDITIONS
Range of use
-10 to 40°C, while batteries are charging
-10 to 55°C, during measurement
10 to 80 % relative humidity
0.01
0.005 ... 9.999 µF
10.00 ... 49.99 µF
1 nF
± 10% + 1 ct
500 V
500 k
6500
108
10 nF
± 10%
1000 V
2500 V
1 M
2.5 M
5500
4000
5000 V
5 M
1500