Mode Selection; Choice Of Range; Measurement Value Display; Measurement Inputs - Hameg HM 8012 Manual

(16) Unit display zone (LED)
This zone contains a display of the measurement
units. It also identifies the function selected by
pressing the (18) or
(17) AC-DC (pushbutton)
This key is used for selecting the measurement
mode (DC, rms AC or rms AC + DC).
Indicators below indicate the measurement mode:
DC: measurement of DC voltages
AC: measurement of RMS AC voltages
DC + AC: measurement of RMS AC+DC
voltages.
(18) (pushbutton)
Pushbutton for selecting the next function.
(19) (pushbutton)
Pushbutton for selecting the previous function. On
startup, the unit switches automatically to the DC
voltmeter, MANUAL mode function and 1000-Volt-
Range.
Choice of multimeter functions
Beginning in Volt-Range (V) by using the keys
and (18) you can step through all the multimeter
functions one by one, in following order:
DC or AC voltages. Input on the V/Ω/T°/dB and
COM connectors.
The measurement of DC or AC voltages in
decibels (reference 1mW/600Ω). Input to V/Ω/
T°/dB and COM connectors.
DC or AC current up to 500 mA. Inputs on mA/
µA and COM connectors.
DC or AC current, 10 A range. Inputs on the A
and COM connectors.
Resistors. Inputs V/Ω/T°/dB and COM
connectors.
Temperature in degrees Celsius. Connection of
probe to V/Ω/T°/dB and COM connectors.
Temperature in degrees Fahrenheit. Connection
of probe to V/Ω/T°/dB and COM connectors.
Diode test. Inputs on V/Ω/T°/dB and COM
connectors.
On each press, the new function is indicated by an
LED corresponding to the unit of the quantity to be
measured. It is possible to move from one function
directly to any other function by a successive series
of pressings.

Mode selection

For current and voltage modes, the AC-DC key is
used for choosing between DC voltage
measurement, AC or AC + DC true rms voltage
measurement.
Subject change without notice
(19) key.

Choice of range

In manual mode, the and keys are used for
switching between the various measurement
ranges. The measurement ranges are split into
decades. After each range change, a code appears
indicating the new range being used. This code is
in LX form, where X is a value that may vary from
1 to 6 depending on the range and function and
L1 is the lowest range.
During measurements of unknown voltages or
currents, first choose the highest measurement
range, then switch to the range giving the most
favorable display.
Change to the higher range is obtained when the
value exceeds 51,000 counts. Change to the lower
range is obtained when the value drops below
4,900 counts. It is possible to know which range
has been selected by the unit by temporarily
deactivating the AUTO mode so that the range
indication code appears fleetingly.

Measurement value display

Measurement values are represented by 7
segment LED's display associated with one LED
(19)
for the negative sign. The maximum value of the
1st digit is 5: this corresponds to a 4 3/4 digit
display with a 50,000 counts measurement
capacity. A minus sign appears in front of the
figures when, during DC measurements, the
positive polarity of the measured value is on the
COM terminal. With the inputs short-circuited, the
display indicates (depending on the measurement
range) value zero ± 2 digit. When the range is
overrun, the display shows "OFL " and an audible
beep is emitted repeatedly if it is selected. For
the resistance measurement function, the
exceeding of the capacity (> 50MΩ) generates the
"OPEN" message.
If the multimeter is not connected to a circuit, the
display indicates random values due to the very high
input impedance for ranges of 500mV and 5V.

Measurement inputs

HM8012 has four safety terminals with which,
when using appropriate measurement cables (e.g.
HZ15), spurios measurements are totally ruled out.
As a safety measure the measurement cables
should be checked periodically for insulation faults
and, when necessary, be replaced. The "COM"
terminal (black) is common to all the measurement
ranges. The potential close to ground of all the
measurement quantities should be applied to this
terminal. The input mA/µA (blue) and A (blue) is
intended only for current measurements, whereas
the input V/Ω/T°/dB is designed for all other
measurements. Each terminal is appropriate to
receive 4 mm banana plugs.
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