Trotec T500 Manuel D'utilisation page 63

Possible causes of a faulty calibration are a contaminated electrode
head, a defective sensor circuit or an object which has touched the
measuring spikes during the measurement.
Clean the electrode head if need be, ensure that the measuring
spikes are not contacting any other objects and try to repeat the cal-
ibration procedure after switching on again. If this action is unsuc-
cessful, the device may be defective.
Display: "BAT LO"
battery must be replaced without delay.
Operating manual – English
Explanation: If the battery is almost exhausted, "BAT
LO" appears in the display and an operating time of
a few hours remains, depending on the operating
mode. If no automatic calibration is carried out, but
instead "BAT LO" continues to be displayed, the
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