Using The Mag690; Cabling; Connecting Power; Response - Bartington Mag690 Operation Manual

5. Using the Mag690

5.1. Cabling

Note: The connecting cable to the sensor should be an eight-core screened cable. Two
cores will be used for positive and negative power supply lines, three cores for output
signals, one core for signal common and one for power supply ground. The screen should
be connected to supply ground at the supply end only. The capacitance between cores
should be less than 200pF per metre. A cable with individually shielded cores should be
considered for long cable applications.
Note: Leads are susceptible to EM interference and should be screened wherever possible.
Note: The length of the cable is limited by the voltage drop in the power supply lines
and the capacitance between the cores. For this reason the cable should be limited to a
maximum length of 600 metres.
Bartington Instruments can supply cables for connecting the sensor to the PSU1, Magmeter-2,
SCU1, Spectramag-6 and Mag-03DAM.

5.2. Connecting Power

Caution: Check that the polarity of the supply is correct. The power supply should
be connected to the sensor before the supply is energised as this prevents high
surge currents which could cause damage. Apply the positive and negative supplies
simultaneously, and avoid leaving the sensor connected to one polarity only.

5.3. Response

The analogue output of any channel, will be proportional to the magnetic field present in the
direction of the fluxgate sensing element. The proportionality factor (scaling factor) can be found
in the product brochure.
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