Amprobe PM55A Automatic-Precision-Pocket-Meter - Manual (Page 7)

5
AutoTect

Mode
This AutoTect
 feature automatically selects measurement function of
V dc, V ac, or resistance based on the input via the test leads.
● With no input, the meter displays Auto when it is ready.
● With no voltage signal but a resistance below 6 M
Ω is present, the meter displays the resistance
value.
● When a signal above the threshold of 1.2 V dc or 1.5 V ac up to the rated 600 V is present, the
meter displays the appropriate voltage value in dc or ac, whichever larger in peak magnitude. The
H appears indicating ac V. The default of no icon is dc V.
● The AutoTect test mode input impedance is lower than most digital multimeters and LoZ is
displayed on the LCD. Switch to the manually selected V dc or V ac, if the circuit being tested is
sensitive to the meter input impedance. Input impedance is approximately 900
Ω, helping
determine if voltage is from leakage (so-called “ghost” voltages) or a hard connection. “Ghost”
voltages will be zeroed out by the low input impedance.
● Overload-Alert Feature
When more than 600 V is present, the meter displays OL with a warning beep tone. Disconnect
the test leads from the signal immediately to avoid hazards.
• Range-Lock Feature
When a measurement reading is displayed in the AutoTect
 mode, press the SELECT button
momentarily to lock the function-range. The LCD annunciator Auto turns off. Range-lock can
speed up repetitive measurements. Press the SELECT button momentarily again to return to
AutoTect
 mode.
• When making resistance measurements in AutoTect 
mode, an unexpected display of voltage
readings alerts you that the circuit under test is still energized.
Continuity, Audible With Symbolic Display
With Auto on the LCD, press the SELECT button once to select Continuity function. The meter will
show a symbolic open-switch display
when it is ready. A continuous beep tone and a symbolic
closed-switch indicates a closed circuit. Continuity is used for checking wiring connections and
operation of switches.
Electric Field EF-Detection, VolTect

With Auto displayed on the LCD, press the SELECT button momentarily 2 times to select the EF-
Detection feature. The meter displays EF when it is ready. Signal strength is indicated as a series of
bargraph segments on the display and variable beep tones. See the VolTect
 specifications later in
this manual for a complete description of the bar graph indicators.
• An antenna is located at the top left corner of the meter, which detects electric field surrounding
current-carrying conductors. It is ideal for tracing live wiring connections, locating wiring
breakage and to distinguish between live or earth connections.