INTRODUCTION
Thank you for purchasing General Tools & Instruments’ CMR35 Series Wireless Data
Logging Clamp Multimeter System. Please read this user’s manual carefully and
thoroughly before using the instrument.
There are two CMR35 systems: The CMR35 system operates at 910MHz and the
CMR35A system operates at 912.4MHz. The basic CMR35 system consists of one
CMR35T clamp meter/ transmitter, one CMR35R data logging receiver (operating at the
same frequency), a USB cable and an installation CD containing data logging software
and a set of USB drivers. Up to six transmitters on different channels can be interfaced
to one receiver operating at the same frequency. The system is designed for use by
industrial maintenance, repair and operations (MRO) professionals.
Used alone or with the receiver, the multimeter’s clamp-type transmitter can measure AC
or DC voltages up to 600 Volts, AC or DC currents up to 600 Amperes, electrical resistances
up to 4MΩ, and the frequency of AC voltages and currents up to 100 kHz. Autoranging is
automatic for all measurements. The transmitter can also verify the integrity of diodes and
perform yes/no checks of continuity between any two points of a circuit.
When a transmitter and receiver are wirelessly connected—at a maximum distance of
328 ft. (100m), with no obstructions in between—measurements made by the trans mitter
can be displayed remotely and in real time on the receiver’s display. Measure ments also can
be time-stamped by the included data logging software and transferred from the receiver to
a Windows
™
computer via a USB cable. As the computer stores the measurements, they can
be viewed in the software’s Monitor window in real time. Measurement logs also can be
viewed and saved on the computer as tabular or graphical data.
The CMR35 system is powered by four “AA” batteries (two each for the transmitter
and receiver).
SAFETY PRECAUTIONS
• WARNING
To prevent electrical shock, fire or damage to the multimeter:
• Never attempt to measure voltages above 600 Volts or currents above 600 Amperes.
• Make sure the transmitter’s function switch is in the correct position for the
parameter to be measured.
• Check that the transmitter’s probes fit snugly in their jacks whenever using them to
make measurements.
• Keep your hands under the guard ring (see Fig. 1) when using the clamp.
• Before switching functions, remove the probes from the circuit under test, and
remove conductors from the jaws of the clamp.
• Before conducting resistance tests, make sure the power to the circuit under test
has been switched off.
• Never use the multimeter in the rain or snow, or with wet hands.
• Do not use the transmitter if its case or probes have been cracked or damaged.
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