Fluke 2635A service manual A/2625A Specifications 2620A Options IEEE-488 Option -05K, Typical

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Service Manual

Table 1-3. 2620A/2625A Specifications (cont)

2620A Options

IEEE-488 (Option -05K)

Capability codes:SH1, AH1, T5, L4, SR1, RL1, PP0, DC1, DT1, E1, TE0, LE0 and C0

Complies with IEEE-488.1 standard

Crosstalk Rejection

AC signals can have effects on other channels(crosstalk). These effects are discussed here by measurement function. These numbers should only be considered as references. Since crosstalk can be introduced into a measurement system in many places, each setup must be considered individually.

The effect of crosstalk could be much better than shown for "Typical"; in extreme cases, the effect could be worse than the "Worst Case" numbers.In general, the "Worst Case" information assumes that none of the guidelines for minimizing crosstalk(Section 5) have been followed; the "Typical" information assumes that the guidelines have been followed where reasonable.

These numbers assume that input L (low) is tied to earth ground; refer to "Using Shielded Wiring" in Section 5. For dc volts and thermocouple temperature measurements, a source impedance of 1 kΩ in series with the H (high) input is assumed (except where otherwise noted.)

AC Signal Crosstalk in a DC Voltage Channel

		⎡		⎤
	DCV Error Tatio (CTRR) =	⎢	VDC (error)	⎥
		⎣ VAC rms		⎦
Frequency	Worst case			Typical
50, 60 Hz, ±0.1%:	1.1 x 10-7			2.0 x 10-8
Other Frequencies:	3.8 x 10-6			8.6 x 10-7

For example, to find the typical effect of a 300V ac signal at 60 Hz on another channel for the 300 mV range, you would calculate: 300 X 2.0 X 10-8= 0.01 mV.

AC Signal Crosstalk into an AC Voltage Channel

ACV Error Ratio =	⎡			VAC rms (error)			⎤
	⎢						⎥
	⎣ VAC rms (crosstalk) x Frequency (crosstalk) ⎦
Range	Ratio (worst case)						Ratio (typical)
300.00 mV	4.8 x 10	-8	⎡	V	⎤	1.4 x 10		-8	⎡	V	⎤
			⎢		⎥				⎢		⎥
			⎣ V x Hz ⎦						⎣ V x Hz		⎦
3.0000V	1.1 x 10	-7	⎡	V	⎤	3.0 x 10		-8	⎡	V	⎤
			⎢		⎥				⎢		⎥
			⎣ V x Hz ⎦						⎣ V x Hz		⎦
30.000V	1.2 x 10	-6	⎡	V	⎤	2.6 x 10		-7	⎡	V	⎤
			⎢		⎥				⎢		⎥
			⎣ V x Hz ⎦						⎣ V x Hz		⎦
150.00/300.00V	1.2 x 10	-5	⎡	V	⎤	3.4 x 10		-6	⎡	V	⎤
			⎢		⎥				⎢		⎥
			⎣ V x Hz ⎦						⎣ V x Hz		⎦

For example, to find the typical effect of a 60 Hz, 220V ac signal on another channel for the the 300 mV range, you would calculate: 220 X 60 X 1.4 X 10-8= 0.18 mV.

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