Elma BM 251s-257s
side 39
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. 2.5
kΩ 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 2.5
kΩ 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 566mA (1000V x 1.414 / 2.5
kΩ), decreasing abruptly to approx.
3.8mA (1000V x 1.414 / 375
kΩ) 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.
DCV, ACV, & Line Frequency functions
Press the Hz push-button for one second or more to activate or to exit Hz.
!
DCV
JACK
JACK
ACV
!
JACK
JACK
!
JACK
JACK
Hz
