Agilent Technologies 34401A manual DC Characteristics Measuring Characteristics

Chapter 8 Specifications

DC Characteristics

Measuring Characteristics

DC Voltage
Measurement Method:	Continuously integrating, multi-slope III
	A/D converter.
A/D Linearity:	0.0002% of reading + 0.0001% of range
Input Resistance:
0.1 V, 1 V, 10 V ranges	Selectable 10 MΩ or >10 GΩ		[11]
100 V, 1000 V ranges	10 MΩ ±1%
Input Bias Current:	< 30 pA at 25°C
Input Terminals:	Copper alloy
Input Protection:	1000 V on all ranges
Resistance
Measurement Method:	Selectable 4-wire or 2-wire ohms.
	Current source referenced to LO input.
Max. Lead Resistance:	10% of range per lead for 100 Ω		, 1 kΩ
(4-wire ohms)	ranges. 1 kΩ per lead on all other ranges.
Input Protection:	1000 V on all ranges
DC Current
Shunt Resistor:	0.1Ω for 1A, 3A. 5Ω	for 10 mA, 100 mA
Input Protection:	Externally accessible 3A, 250 V fuse
	Internal 7A, 250 V fuse
Continuity / Diode Test
Response Time:	300 samples/sec with audible tone
Continuity Threshold:	Adjustable from 1 Ω	to 1000 Ω

Operating Characteristics [ 8 ]

			Additional
Function	Digits	Readings/s	Noise Error
DCV, DCI, and	61⁄2	0.6 (0.5)	0% of range
Resistance	61⁄2	6 (5)	0% of range
	51⁄2	60 (50)	0.001% of range
	1⁄	300	0.001% of range	[10]
	5 2
	41⁄2	1000	0.01% of range [10]
System Speeds [ 9 ]
Function Change			26/sec
Range Change			50/sec
Autorange Time			<30 ms
ASCII readings to RS-232			55/sec
ASCII readings to GPIB			1000/sec
Max. Internal Trigger Rate			1000/sec
Max. External Trigger Rate to Memory			1000/sec
Max. External Trigger Rate to GPIB			900/sec

Autozero OFF Operation

Following instrument warm-up at calibration temperature ±1°C and <10 minutes, add 0.0002% range additional error + 5 ∝V.

Settling Considerations

Reading settling times are affected by source impedance, cable dielectric characteristics, and input signal changes.

Measurement Considerations

DC:DC Ratio
Measurement Method:		Input HI-LO / Reference HI-LO
	Input HI-LO	100 mV to 1000 V ranges
	Reference HI-Input LO	100 mV to 10 V ranges (autoranged)
	Input to Reference	Reference LO to Input LO voltage < 2 V
		Reference HI to Input LO voltage < 12V
	Measurement Noise Rejection
	60 Hz ( 50 Hz ) [ 5 ]
	DC CMRR		140 dB
	Integration Time		Normal Mode Rejection [ 6 ]
	100 PLC / 1.67s (2s)		60 dB [ 7 ]
	10 PLC / 167 ms (200 ms)		60 dB [ 7 ]
	1 PLC / 16.7 ms (20 ms)		60 dB [ 7 ]
	0.2 PLC / 3 ms (3 ms)		0 dB
	0.02 PLC / 400 ∝s (400 ∝s)		0 dB

[12]Accuracy specifications are for the voltage measured at the input terminals only. 1 mA test current is typical. Variation in the current source will create some variation in the voltage drop across a diode junction.

Agilent recommends the use of Teflon￿ or other high-impedance, low-dielectric absorption wire insulation for these measurements.

[ 1 ] Specifications are for 1-hour warm-up at 61⁄2 digits.

[ 2 ] Relative to calibration standards.

[ 3 ] 20% overrange on all ranges, except 1000 Vdc, 3 A range.

[ 4 ] Specifications are for 4-wire ohms function, or 2-wire

	ohms using Math Null. Without Math Null, add 0.2 Ω
	additional error in 2-wire ohms function.
[ 5 ]	For 1 kΩ unbalance in LO lead.
[ 6 ] For power-line frequency ± 0.1%.
[ 7 ]	For power-line frequency ± 1%, subtract 20 dB.
	For ± 3%, subtract 30 dB.

[ 8 ] Readings speeds for 60 Hz and ( 50 Hz ) operation,

	Autozero Off.
[ 9 ]	Speeds are for 41⁄2 digits, Delay 0, Autozero OFF,
	and Display OFF. Includes measurement and data
	transfer over GPIB.
[ 10 ]	Add 20 ∝V for dc volts, 4 ∝A for dc current, or
	20 mΩ for resistance.
[ 11 ]	For these ranges, inputs beyond ±17V are
	clamped through 100 kΩ (typical).

Teflon is a registered trademark of E.I. duPont deNemours and Co. 8

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