Fluke 2625A, 2620A user manual In More Detail

2620A, 2625A

Users Manual

1.Connect the shield to L (low) at the 2620A-100 Input Module, and try connecting the sensor shield to a quiet earth ground at or very near the measurement sensor end (and at only one place), or

2.Connect the shield to L (low) at the Input Module, and try connecting the shield to earth ground (only) as close to the rear of the instrument as possible. Isolated and shielded sensors will likely result in the best instrument measurement performance possible in a noisy environment.

In More Detail

If a low noise configuration is required, adhering to the following two rules minimizes measurement errors and noise when using shielded sensors and wiring:

1.Connect the shield so that it and the L (low) terminal are at the same or very nearly the same voltage, and

2.Connect the shield so that common-mode voltages will not cause current to flow through the L (or H) source resistance(s).

One key to applying these rules is to note that very high, but finite impedances exist between H (high) and L (low), between H and earth ground, and between L and earth ground inside the instrument.

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