Averaging; Setting Of Instrument Parameters; Menufunction Setup - Hameg HM8118 Operator's Manual

F i r s t - t i m e o p e r a t i o n
MAN: A measurement will be triggered by pressing the TRIG/
UNIT button.
EXT: a rising slope at the external trigger input will start a
measurement. In the course of a measurement any signals at
this input will be ignored until the cycle has been completed.
The TRIG/UNIT button will light up any time a measurement was
started. Each trigger will only generate one measurement.
Averaging may also be used with manual or external triggering;
the number of measurements will be given by the number of
averaging periods selected.

Averaging

If the function AVG is selected the average of a number of
measurements will be calculated and displayed. For the selec-
tion of the number of measurements press SELECT
menu SETUP and choose AVG: the number may be chosen from
2 to 99 or MED. The display will show „AVG" if this function is
active. If MED is selected, the HM 8118 will perform 6 measure-
ments, it will discard the smallest and the highest and average
the remaining 4 results. This method is handy for eliminating
single erroneous results; e.g. if a component is inserted into
a test fi xture, the fi rst measurement will in general be wrong
because contact is made during a measurement cycle, so this
fi rst result will differ substantially from the following correct
ones. So this fi rst wrong result will be discarded.

Setting of instrument parameters

The instrument parameters can be selected by pressing the SE-
3
LECT button and by calling the menus SETUP, CORR, SYST,
BIN. The buttons L-R/2 , C-D/3
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to select the associated submenus. Depending on the function,
the parameters may be selected using the lighted arrow buttons
6
and the KNOB . The parameter selected may be edited by
pressing the KNOB, the display will show a blinking „E" (for edit).
Numerical values may also be entered via the keyboard; this may
be done by any of the following methods: fi rst select the parame-
ter, then press SELECT or TRIG/MODE/ENTER
6
again, this will open a fi eld in the display which may or may
not also show the unit (depends upon the parameter). Following
the numerical entry, the preselected unit may be changed by
pressing TRIG/MODE/ENTER or the KNOB. The numerical entry
will be stored upon pressing TRIG/MODE/ENTER or the KNOB.
Use the BIAS/ button to modify an incorrect entry.
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Subject to change without notice
3 , use the
3
, C-R/4 , R-Q/5 are used
34 32 30
or the KNOB
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Menufunction SETUP

The submenu of SETUP allows the following settings:
Frequency FRQ
The measuring frequency may be set from 20 Hz to 200 kHz.
Voltage LEV
The measuring voltage may be set from 20 mV
BIAS voltage or current
A voltage bias may be set from 0 to + 5 V (internal) or from 0 to
+ 40 V (external). A bias current may be set from 0 to + 200 mA
(internal). The bias voltage or current can be turned on/off.
Measuring range RNG
The ranges may be selected automatically or manually from 3
ohms to 500 kΩ.
Measuring speed SPD
The speed may be selected from SLOW (1.5 meas./sec) to MED
(8 meas./sec) to FAST (14 meas./sec).
Triggering TRIG
The trigger source and the trigger mode are selected here:
CONT (continuously), MAN (manually), EXT (externally).
Delay
A trigger delay may be selected from 0 to to 40,000 ms (40 s).
Averaging AVG
Averaging can be turned on/off, also the number of measure-
ment cycles to be averaged can be set here from 2 to 99, or the
mode MED selected.
Display of test signal levels voltage V
Here, the display of the voltage and current at the component's
terminals may be turned on/off.
Guarding GUARD
For guarded measurements two modes are available: AUTO
(automatic) or DRIVE. Guarding is used at low voltage levels.
Deviation DEV_M:
The display of the percentage or absolute (ABS) deviation of the
measured main value from the reference value REF_M can be
turned on/off.
Reference REF_M:
A measured value may be entered as the reference into the
main (M) reference memory. The following units are allowed:
H, mH, μH, nH, F, mF, μF, nF, pF, Ω, mΩ, kΩ, MΩ, or S, kS, mS,
μS, nS, pS. As long as this fi eld is open, the actual measured
value of the DUT may be set as the reference by pressing the
button TRIG/UNIT .
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to 1.5 V .
rms rms
and current I
m m