HT instruments HT401 - Manual (Page 9)

HT401
EN - 8
4.3. INTERNAL MODES OF INSTRUMENT
4.3.1. PEAK/HOLD
mode
When operating in PEAK/HOLD function, the instrument records the Max or Min voltage or
current peak values. When a new MAX peak value or MIN peak value is detected, the
instrument saves the new values. Press the key again to stop recording peak values.
Press and hold the MIN/MAX key for 2 seconds to activate the PEAK HOLD mode.
Press and hold the MIN MAX key for more than 1 second or turn the selector to exit the
function.
4.3.2. AC+DC
mode
In the voltage and current measurements by pressing MODE key the selection of “AC+DC”
measurement mode is possible. This mode permits the evaluation of possible DC
components overlapped on a generic alternate waveform signal and this can be very
useful for the measurements on impulsive signals typically of non-linear loads (e.g:
welders, electric ovens, etc).
4.3.3. AutoV LoZ mode
This mode permits to perform the AC voltage measurement with a low input impedance in
way to avoid the wrong rdg due to stray voltage in capacitive coupled
CAUTION
Inserting the instrument between phase and ground conductors, the RCDs
protection devices can be tripping out during the test. In this case the
measurement can be performed only inserting the instrument between
phase and neutral conductor firstly checking the neutral electrical potential
4.3.4. Disabling the Auto Power OFF function
In order to preserve internal batteries, the instrument switches automatically off
approximately 20 minutes after it was last used. The symbol “APO” appears on the display
when this function is active. When the instrument must be used for long periods of time, it
may be useful to deactivate the Auto Power Off function as follows:
 Switch off the instrument (OFF)
 Switch on the instrument by turning the rotary switch and pressing and holding the
MODE key. The “AoFF” message is shown at display
 Switch off and on the instrument to automatically enable the feature
4.3.5. Wrong insertion indication
A continuous sound and a “Prob” message are shown by the instrument in case of wrong
insertion of test leads according to the position of function selector. Fit the test lead in the
correct configuration in way to stop the alarm condition