Memory (Hold); Filter; Dielectric Absorption Index (Dai); Polarization Index (Pi) - Circutor MD-5060e Guia Del Usuario

Memory (HOLD)

When / key is pressed the instrument is at the memory function and, therefore, holding the value of the last
performed measurement on the display.

Filter

When are made measurements of transformers or machines of great dimensions, in the presence of great electro-
magnetic fields, is possible that the reading of the equipment be unstable, over all for values of resistance greater
than 300MΩ. In these cases is advisable to press FILTER key before initiating the measurement.

Dielectric absorption index (DAI)

For this kind of tests, the apparatus should be connected, applying high voltage to the sample for 1 minute (60
seconds). After this period, the operator must press the DAI ; key to read the absorption index value on the display.
If this key is pressed before the 1-minute period has elapsed, the display will show DAI = - - -.
The Dielectric Absorption Index is the ratio between the insulation resistance value measured after 60 seconds and
the value measured after 30 seconds. This value is useful to determine whether it is necessary to perform preventive
maintenance on the coils (transformers, engines and motors, generators, etc.).

Polarization index (PI)

For this type of tests, the megger must be connected and apply high voltage to the sample for 10 minutes. After this
period, the operator must press the PI key 9 to display the PI value on the megger display. If the key is pressed
before the 10-minute period has elapsed, the display will show PI= - - -.
The polarization index is the ratio between the insulation resistance value measured after 10 minutes and the value
measured after 1 minute.
The polarization index is useful to determine whether it is necessary to perform preventive maintenance. In addition, it
is useful to detect any insulation resistance wear and tear due to the excess of dust, grease, or else the action of
chemical or physical agents, etc.

Battery test

During the measurement, check if the battery is charged. Press the "BATTERY" key -, and check the display infor-
mation. If the charge is enough, it will read "BAT OK" or "LOW BAT", should it be recharged. The analogue bar-graph
will give an approximate idea of the remaining charge percentage (at least 20% is required for a normal operation).
R
DAI =
60 sec
R
30 sec
R
PI =
10 minutes
R
1 minute
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