HP 6205B NOTE, CAUTION, 5-8TEST EQUIPMENT REQUIRED

TM 11-6625-2965-14&P

5-8 TEST EQUIPMENT REQUIRED

5-9 Table 5-1lists the test equipment required to perform the various procedures described in this Section.

NOTE

A satisfactory substitute for a differential voltmeter is to arrange a reference voltage source and null detector as shown in Figure 5-3. The reference voltage source is adjusted so that the voltage difference between the supply being measured and the reference voltage will have the required resolution for the measurement being made. The voltage difference will be a function of the null detector that is used. Examples of satisfacto-

ry null detectors are: 419A null detector, a dc coupled oscilloscope utilizing differential input, or a 50mV meter movement with a 100 division scale. For the latter, a 2mV change in voltage will result in a meter deflection of four divisions.

Figure 5-3. Differential Voltmeter Substitute,

Test Setup

CAUTION

Care must be exercised when using an electronic null detector in which one input terminal is grounded to avoid ground loops and circulating currents.

Table 5-1. Test Equipment Required

TYPE		REQUIRED					USE		RECOMMENDED
	CHARACTERISTICS								MODEL
Differential	Sensitivity: lmV			full scale	Measure	dc	voltages;		3420 (See Note)
Voltmeter	(min.). Input		impedance:		calibration		procedures
	10 megohms		(min.).
Variable	Range: 90-130 Volts				Vary ac	input
Voltage	Equipped with voltmeter ac-
	curate within		1 Volt.
AC Voltmeter	Accuracy:	2%.		Sensitivity:	Measure	ac	voltage and		403 B
	lmV full	scale		deflection	ripple
	(min.).
Oscilloscope	Sensitivity: 10µV/cm. Differ-				Display	transient		response	140 A plus
	ential input.				waveforms				1402A plug in.
Oscillator	Range: 5Hz to 600kHz				Impedance		Checks		200 CD
	Accuracy:	2%
DC Voltmeter	Accuracy: 1%. Input resist-				Measure	dc	voltages		4 1 2 A
	ance: 20,000 ohms/Volt (min.).
Repetitive	Rate: 60-400 Hz, 2µsec rise				Measure	transient		response	See Figure 5-6
Load Switch	and fall time.

5-2