User Manual

4 GMC-I Messtechnik GmbH
The information which appears at the display varies depending on
the selected function.
2.3 Initial Start-Up
After inserting the batteries in accordance with section 6.1 on
page 9, the measuring instrument is ready for operation.
3 Performing Measurements
3.1 Switching the Instrument On and Off, Energy-Saving
Mode, Automatic Shutdown
The instrument is switched on by pressing and holding the START
key. Briefly press the START key twice in order to switch the instru-
ment off, during which no voltage may be applied to the test
probes! The instrument is switched to the standby mode after
several seconds (reduced brightness), if none of the keys has
been pressed and no voltage is applied to the test probes. The
instrument is switched out of the standby mode (i.e. back to full
brightness) by pressing any key or applying voltage to the test
probes. The instrument is shutdown automatically if it has
remained inactive for about 1 minute, i.e. if no keys have been
pressed and no voltage has been applied to the test probes dur-
ing this time.
3.2 Instructions and Principles with Validity for All
Measurements
• The desired functions and parameters are selected with the
~/RCD, T
A
, DISP ▲ and DISP ▼ keys. Measurement is triggered
by pressing the START key. All selected functions or parame-
ters remain valid until they are changed.
• If a voltage of <24V or >260V is applied to the test probes,
corresponding information appears at the display and mea-
surement cannot be triggered by pressing the START key.
• If a voltage within a range of 24 V to 190 V is applied to the test
probes, the START key is disabled and “< 190 V” is displayed.
• If the test instrument displays voltage applied to the test
probes after the START key has been pressed, although no
measurement ensues and the blown fuse symbol appears at
the display, the fuse must be replaced.
• If voltage within a range of 190 V to 260 V is applied to the
test probes, the momentary measured value appears at the
display and measurement can be triggered by pressing the
START key.
• If battery voltage is too low (only the red field is lit up in the
battery symbol), measurement cannot be started. After press-
ing the START key, the depleted battery symbol appears for
about 1 second (see figure below). Replace the batteries as
described in section 6.1 on page 9.
• If several impedance measurements are performed one after
the other, internal warming of the instrument is displayed by
means of the red indicator – “T” symbol. As temperature
increases, the field is gradually filled in and becomes wider.
When the maximum permissible internal temperature has been
exceeded, the “T” symbol is replaced with the “STOP” symbol. If
the START key is pressed and held for approximately 1 second,
overheating is displayed and any further measurements are dis-
abled. Allow the instrument to cool down!
➭ Securely contact the device under test with the test probes.
Afterwards, check to see whether or not the displayed line
voltage value is stable. Always assure good contact during
measurement in order to prevent distortion of the measure-
ment results.
• The test instrument evaluates deviation while measurement is
being performed. If considerable interference occurs within
the measured system during measurement which would lead
to inaccurate impedance measurement results, impedance
does not appear at the display and the instrument is switched
to voltage measurement after measurement has been com-
pleted. The measurement must be repeated!
• If line voltage is unstable while measurement is being per-
formed, or if other electrical circuits parallel to the measured
circuit are in use, measurement results may be distorted and
permissible measuring error may be exceeded.
Figure 3.1:Voltage < 24 V
(brief representation)
Figure 3.2: Voltage < 24 V
(detailed representation)
Figure 3.3: Blown Fuse Example
(detailed representation)
Figure 3.4: Voltage Measurement
(brief representation)
Figure 3.5: Voltage Measurement
(detailed representation)
Figure 3.6: Low Battery Voltage
(detailed representation)
Figure 3.7: Display After Pressing START
(detailed representation)
Figure 3.8: High Temperature Display
(brief representation)
Figure 3.9: High Temperature Display
(detailed representation)
Figure 3.10: Overheating Display – STOP
Symbol
Figure 3.11: Overheating Display After
Pressing the Start Key