Dc Measurement And Operating Characteristics - Agilent Technologies 34970A Service Manual

Chapter 1 Specifications

DC Measurement and Operating Characteristics

DC Measurement and Operating Characteristics
DC Measurement 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:
100 mV, 1 V, 10 V ranges
Selectable 10 M
100 V, 300 V ranges
10 M
Input Bias Current:
< 30 pA at 25
Input Protection:
300 V on all ranges
Resistance
Measurement Method: Selectable 4-wire or 2-wire Ohms,
Current source reference to LO input
Offset Compensation: Selectable on 100
Max. Lead Resistance:
10% of range per lead for 100
1 k
Input Protection:
300 V on all ranges
DC Current
Shunt Resistance: 5
Ω
Input Protection:
1.5A 250 V fuse on 34901A module
Thermocouple
Conversion: ITS-90 software compensation
Reference Junction Type: Internal, Fixed, or External
Open T/C Check:
Selectable per channel. Open > 5 k
= 0.00385 (DIN) and 0.00391
α
RTD
44004, 44007, 44006 series
Thermistor
Measurement Noise Rejection 60 Hz (50 Hz)
DC CMRR: 140 dB
Integration Time Normal Mode Rejection
200 PLC / 3.33s (4s) 110 dB
100 PLC / 1.67s (2s) 105 dB
20 PLC / 333 ms (400 ms) 100 dB
10 PLC / 167 ms (200 ms) 95 dB
2 PLC / 33.3 ms (40 ms) 90 dB
1 PLC / 16.7 ms (20 ms) 60 dB
< 1 PLC
[1]
Ω or >10 G Ω
1%
Ω ±
C
°
, 1 k , 10 k ranges
Ω Ω Ω
and
Ω
Ω ranges. 1 k Ω on all other ranges
for 10 mA, 100 mA; 0.1 for 1A.
Ω
[2]
[3]
[4]
[4]
[4]
[4]
0 dB
DC Operating Characteristics
Function Digits
DCV, DCI, and 6
Resistance: 6
5
5
4
Single Channel Measurement Rates
Function
DCV, 2-Wire Ohms:
Thermocouple:
RTD, Thermistor:
Autozero OFF Operation
Following instrument warm-up at calibration temperature
and < 10 minutes, add 0.0002% range additional error + 5
Ω
Settling Considerations
Reading settling times are affected by source impedance,
low dielectric absorption characteristics, and input signal changes.
[1] 300 Vdc isolation voltage (ch-ch, ch-earth)
[2] For 1 k unbalance in LO lead
Ω
[3] For power line frequency
[4] For power line frequency
For power line frequency
[5] Reading speeds for 60 Hz and (50 Hz) operation; autozero OFF
[6] 6 digits=22 bits, 5
1 1
⁄
2
[7] Add 20 µ V for DCV, 4
[8] For fixed function and range, readings to memory,
scaling and alarms off, autozero OFF
[5]
Additional
[6]
Readings/s Noise Error
0.6 (0.5) 0% of range
1
⁄
2
6 (5) 0% of range
1
⁄
2
60 (50) 0.001% of range
1 ⁄
2
300 0.001% of range
1
⁄
2
600 0.01% of range
1
⁄
2
[8]
Resolution Readings/s
6 (10 PLC) 6 (5)
1
⁄
2
5 1 (1 PLC) 53 (47)
⁄
2
4 (0.02 PLC) 490
1
⁄
2
0.1 ° C (1 PLC)
49 (47)
° C (0.02 PLC) 280
0.1
0.01 C (10 PLC) 6 (5)
°
47 (47)
0.1 ° C (1 PLC)
280
1 ° C (0.02 PLC)
0.1%
±
± 1%, use 80 dB.
± 3%, use 60 dB.
digits=18 bits, 4 digits=15 bits
1
⁄ ⁄
2 2
µ A for DCI, or 20 m Ω for resistance
1
[7]
[7]
± 1 ° C
V.
µ
17