Operation Manual

Elma BM 82X & BM52X Page 66
Note:
*Range-Lock and Function-Lock Feature: When a measurement reading is being
displayed in AutoCheck
TM
mode, press the RANGE or SELECT button momentarily 1 time
can lock the range or function it was in. Press the button momentarily repeatedly to step
through the ranges or functions.
*As Hazardous-Alert: When making resistance measurements in AutoCheck
TM
mode, an
unexpected display of voltage readings alerts you that the object under test is being
energized.
*Ghost-voltage Buster: Ghost-voltages are unwanted stray signals coupled from
adjacent hard signals, which confuse common multimeter voltage measurements. Our
AutoCheck
TM
mode provides low (ramp-up) input impedance (approx. 3kΩ at low voltage)
to drain ghost voltages leaving mainly hard signal values on meter readings. It is an
invaluable feature for precise indication of hard signals, such as distinguishing between
hot and open wires (to ground) in electrical installation applications.
WARNING:
AutoCheck
TM
mode input impedance increases abruptly from initial 3kΩ to a few hundred
kΩ’s on high voltage hard signals. “LoZ” displays on the LCD to remind the users of being
in such low impedance mode. Peak initial load current, while probing 1000VAC for
example, can be up to 471mA (1000V x 1.414 / 3kΩ), decreasing abruptly to approx.
3.1mA (1000V x 1.414 / 460kΩ) within a fraction of a second. Do not use AutoCheck
TM
mode on circuits that could be damaged by such low input impedance. Instead, use rotary
selector or high input impedance voltage modes to minimize loading for such
circuits.
dBm
+Hz
(829 only), Hz
+ACV
, ACV
+Hz
functions
Press the SELECT button momentarily to select the subject functions in sequence. Last
selection will be saved as power up default for repeat measurement convenience.