42
Instrument Functions
In this case it is necessary to short circuit the measurement
cables and then press the NULL key. This triggers the offset
correction of the entire measurement section. This value
will be shown on the display below the main measurement
value. The line resistance of the measurement cable, con-
tact resistances and thermoelectric voltages between diffe-
rent metals have been intentionally eliminated by this offset
correction. The compensation values will not be stored
after the ¸HMC8012 has been switched off and have to
be redetermined. In addition, you may also enter the NULL
value numerically or via knob.
On page 2|2 of the Ω main menu, you can use the soft
menu key Mode to distinguish between 2-wire operation
(2w) and 4-wire operation (4w - (4w - connect SENSE
cables).
The soft menu key ADC Rate and the knob allow you to
set the display refresh rate for the 2-wire operation (2w) to
Slow (5 measurements per second), Medium (10 measure-
ments per second) or „Fast (50 measurements per second).
For the 4-wire operation (4w), you can set the display re-
fresh rate to Slow (5 measurements per second), Medium
(10 measurements per second) or Fast (25 measurements
per second).
5.5 Measuring a Capacity
To measure a capacity, you can connect a capacitor with
the ¸HMC8012 multimeter via silicon measurement
cables and clamp-type test probes, for instance. Use the
COM and V connectors on the bottom. Once the CAP key
on the front panel of the instrument is used, the capacity
value will be shown on the multimeter display.
To compensate for the line resistance of measurement
cables, it is necessary to short circuit the measurement
cables and press the NULL key. This triggers the offset
correction of the entire measurement section. This value
will be shown next to the soft menu key NULL and on
the display below the main measurement value. The line
resistance of the measurement cable, contact resistan-
The maximum accuracy in measurements is achieved when using
the setting „Slow (ADC Rate).
ces and thermoelectric voltages between different metals
have been intentionally eliminated by this offset correc-
tion. The compensation values will not be stored after the
¸HMC8012 has been switched off and have to be rede-
termined. In addition, you may also enter the NULL value
numerically or via knob.
5.6 Measuring Sensors (PT100 / PT500 / PT1000)
Sensor measurements can be performed with various tem-
perature probes. The temperature probes HZ812 (2w) or
HZ887 (4w) are available as optional accessories. Depen-
ding on the type used, you can select „2w“ or „4w“ with
the respective soft menu key. The soft menu key PT Type
allows you to select PT100, PT500 or PT1000 as probe
Fig. 5.7: 2-wire sensor measurement (temperature)
- +
temperature (2-wire)
Fig. 5.5: Measuring resistance (4-wire)
- +
resistance 4-wire
(Ω)
Fig. 5.6: Measuring the capacity
- +
capacity
Fig. 5.8: 4-wire sensor measurement (temperature)
- +
temperature (4-wire)
