20
Operation
4.
Connect the red test lead to the voltage to be measured. The
voltage present between the two test leads will be indicated on
the front panel display.
Voltage Ranges
For the voltage input, the 918B has four different operating ranges.
Depending on the level of voltage applied to the input, the
instrument may automatically switch between ranges. This range
switching is internal, and may or may not be evident in the display.
Automatic range switching can be defeated, using range hold. Refer
to section 3.1, "Automatic and Manual Range Selection", for a
description of the internal ranges, the display ranges, auto-ranging
operation, and range hold operation.
Hold Mode
When making measurements using any of the operating modes of
the 918B, you can "freeze" the values for all measured parameters
by simply pressing the "HOLD" button. You can then switch
between all of the different modes and determine their respective
values at the time "HOLD" was pressed. Pressing "HOLD" a second
time restores the instrument to normal operation.
Min / Max Readings
Recording of minimum and maximum values is suspended for any
period of time that the hold function is active. However, all
previously recorded values are retained. Refer to section 3.2 for
more information on minimum and maximum value recording.
2.5 Measurement of AC Amperes
Using the supplied 1000:1 clamp-on current transformer, the 918B
Phase Angle Multimeter is capable of rms current measurements of
between 0.02 and 20 amperes, over a frequency range of 45 to 500
hertz. For instructions on using other current transformers with
different ratios, refer to section 2.2.1.1. Because an rms-to-dc