GRAPHTEC GL820 - Noise Countermeasures

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CHAPTER 2 Checks and Preparation
2.15 Noise Countermeasures
Be sure to connect the chassis GND of the object to be measured.
It may become effective by ensuring that the chassis GND wire of the measurement object is
connected to a good ground.
Z3
GL820
Z1 Z2
＋
－
Vin
R1
R2
Measurement object
Thermocouple
Input terminals
Connect the signal chassis GND and the measurement device chassis ground.
Use a short, thick lead to connect the chassis GND of the measurement object to the GL820’ chassis
GND. It will become even more effective if the ground potentials are the same.
GL820
GND GND
Measurement device chassis
Noise countermeasures
If measured values fluctuate due to extraneous noise, conduct the following countermeasures.
(Results may differ according to noise type.)
Ex 1 : Connect the GL820’s GND to ground.
Ex 2 : Connect GL820’s GND to measurement object’s GND.
Ex 3 : In the AMP settings menu, set filter to any setting other than “OFF”.
Ex 4 : Operate GL820 with batteries (Option: B-517).
Ex 5 : Set the sampling interval which enables GL820’s digital filter.
Use the “OTHER” menu to set the commercial power frequency you use.
Refer to page 3-39 for details