AEMC Instruments 275HVD Manual De Usuario página 18

NOTE:
Positioning the sensing dome near a computer screen or a TV
screen (not liquid crystal display type) should also trigger the tester
while on the 240 V selection
4.4 HIGH VOLTAGE TESTING
See Warnings on pages 11 and 12
The 275HVD Non-Contact High Voltage Detector works by proximity. It is not
designed to be in physical contact with live conductors. Its sensor detects the
radiated field which surrounds live conductors.
WARNING: Do not touch live conductors with the 275HVD
Non-Contact High Voltage Detector.
Radiated field strength increases with voltage and decreases quickly with
distance and/or ground shielding. The radiated field from a cable where
conductors supplying three-phase power are close together, tends to cancel out
(See § 4.2). The rotary switch (attenuator) is used to identify and differentiate
various HV live cables.
WARNING: The tester must only be used with an appropriate
insulated rod or Hot Stick when measuring High Voltage.
After checking the 275HVD and ensuring its good operation, select the test
range. It is recommended to start with a lower setting than the actual working
voltage, and then to try again with higher settings. The user may also consider
using lower settings to check for lower voltages on a conductor.
With the 275HVD at the end of a hot stick, move towards the live conductor until
its warnings are triggered.
18 Non-Contact, High Voltage Detector Model 275HVD - User Manua