Operating Instructions; Switch; Zero Adjustment; Current Measurement - Wavetek Meterman CT-235 Manuel D'utilisation

3. OPERATING INSTRUCTIONS

Refer to Fig. 1 for the CT-237 and Fig. 2 for the CT-235 (pages 5 & 6).
3.1 Switch On
When the probe is switched on the red LED will illuminate. If the LED starts
flashing this warns the user that the battery voltage is too low for normal
operation and that it should be changed as described in section 5.

3.2 Zero Adjustment

The output zero offset voltage of the probe may change due to thermal shifts and
other environmental conditions. To adjust the output voltage to zero depress
the thumbwheel and rotate. Ensure that the probe is away from the current
carrying conductor whilst the adjustment is made.

3.3 Current Measurement

Switch on the probe using the On - Off switch and check that the LED is lit.
Select the required current range ( 20 Amp or 200 Amp for the CT-237; 200A
or 1000A for the CT-235).
Connect the output lead to a multimeter. Select AC millivolts to measure
Alternating Current and DC millivolts for Direct Current. Autoranging meters
will automatically select the correct range.
If necessary adjust the probe output voltage to zero as described in section 3.2.
Clamp the jaws of the probe round the conductor ensuring a good contact
between the closing faces of the jaws.
Observe and take measurements as required. Positive output indicates that the
current flow is in the direction shown by the arrow on the probe.
True r.m.s. readings can be obtained by using an appropriate true r.m.s. reading
multimeter.
Core eddy current heating is produced when Irms x f >400,000.

4. SAFETY

This instrument is designed to be safe under the following conditions:
- indoor use
- altitude up to 2000m
- temperature 0°C to +50°C
- maximum relative humidity 80% for temperatures up to 31°C decreasing
linearly to 40% relative humidity at 50°C.
Use of the probe on uninsulated conductors is limited to 300V r.m.s or d.c. and
frequencies below 1kHz.
Safety in its use is the responsibility of the operator who must be a suitably
qualified or authorised person.
Do not use the probe if any part of the probe including the lead and connector(s)
appear to be damaged or if a malfunction of the instrument is suspected.
When using the probe ensure that your fingers are behind the protective barrier
see Fig. 1
Clean the case periodically by wiping it with a damp cloth and detergent. Do
not use abrasive cleaners or solvents. Do not immerse the probe in liquids.

5. BATTERY REPLACEMENT

SAFETY WARNING: Before removing the
battery cover, make sure that the probe is
remote from any live electrical circuit.
The red LED will flash when the minimum operating voltage is approached.
Refer to Fig.1. and use the following procedure.
Unclamp the probe from the conductor, turn it off using the On - Off switch and
disconnect the output leads from external equipment. Loosen the captive screw
which secures the battery cover. Lift the cover through 30° and pull it clear of
the probe body as shown in Fig 1. The battery is then accessible. Replace the
battery and re-fit the battery cover and fasten the screw.
Replacement with other than the specified type of battery will invalidate the
warranty. Fit only Type 9 V PP3, Alkaline (MN 1604 ).
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