Tettex MIDAS 2881, Operating Instructions Manual

Page: 55 / 164

Software 45
Mandatory Inputs
All inputs which are preceded with a red asterisk (

) are mandatory fields. That means at least one
character has to be filled in. This “lock-functionality” can be disabled. See section “Menu Settings“ for
more information.
If there is an mandatory input field which has to be filled in, the tab sheet
button at the top is marked with a red asterisk.
When all marked mandatory fields are filled, the red asterisk in the tab
sheet button will switch to a green hook.
7.4.2 Menu Conditions (Temperature correction)
The electrical characteristics of practical all insulation materials vary with temperature. In order to
compare the results of periodic tests on the same equipment it is necessary to know the correction
factors against the temperature. The Midas includes this correction factors for most of the available
test objects and therefore results can automatically be corrected to the reference temperature (20°C,
68°F). To do so the corresponding test object has to be slected in the menu. As information the
correction table will arise in the button of the screen.
Temperature correction data are average values and therefore subject to some error. The error is
minimized if tests are performed at or near to reference temperature. This is not always possible in
the field. But when questionable tan

values are measured at very high or very low temperatures the
equipment should be retested closer to the reference temperature.
To perform the correction, the temperature of the DUT insulation at the moment it is tested has to be
defined. Additionally for information the actual ambient temperature and humidity can be entered.
The test object temperature can be obtained form the DUT temperature indicator or using the laser
temperature/humidity measuring device (optional).
Actual DUT
insulation
temperature
DUT type
selection
Correction
factors table
(information)