Specifications

146
Low-Cost Data Acquisition/Switch 34970A (Continued)
More detailed specifications at www.agilent.com/find/34970A
Data Acquisition & Switching
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 MΩ or >10.000 MΩ
100 V, 300 V ranges 10 MΩ ±1%
Input Bias Current <30 pA at 25°C
Input Protection 300 V all ranges
True RMS AC Voltage Measurement Method AC coupled True RMS – measures the AC component
of the input with up to 300 Vdc of bias on any range
Crest Factor Maximum of 5:1 at full scale
Additional Crest Factor
Errors (non-sinewave) Crest Factor 1–2 0.05% of reading
Crest Factor 2–3 0.15% of reading
Crest Factor 3–4 0.30% of reading
Crest Factor 4–5 0.40% of reading
Input Impedance 1 MΩ ± 2% in parallel with 150 pF
Input Protection 300 Vrms all ranges
Resistance Measurement Method Selectable 4-wire or 2-wire Ohms
Current source referenced to LO input
Offset Compensation Selectable on 100 Ω, 1 kΩ, 10 kΩ ranges
Maximum Lead Resistance 10% of range per lead for 100 Ω and 1 kΩ ranges
1 kΩ on all other ranges
Input Protection 300 V on all ranges
Frequency and Period Measurement Method Reciprocal counting technique
Voltage Ranges Same as AC voltage function
Gate Time 1 s, 100 ms, or 10 ms
Measurement Timeout Selectable 3 Hz, 20 Hz, 200 Hz LF limit
DC Current Shunt Resistance 5 Ω for 10 mA, 100 mA; 0.1 Ω for 1 A
Input Protection 1 A 250 V fuse on 34901A module
True RMS AC Current Measurement Method Direct coupled to the fuse and shunt,
AC coupled True RMS measurement
(measures the AC component ony)
Shunt Resistance 5 Ω for 10 mA; 0.1 Ω for 100 mA, 1 A
Input Protection 1 A 250 V fuse on 34901A module
Thermocouple Conversion Conformity ITS-90 based software routines
Reference Junction Type Internal, Fixed, or External
Open Thermocouple Check Selectable per channel, Open >5 kΩ
Thermistor 44004, 44007, 44006 series
RTD = 0.00385 (DIN) and = 0.00391
Measurement Noise
Rejection 60 (50) Hz
1
DC CMRR 140 dB
AC CMRR 70 dB
Integration Time
Normal Mode Rejection
2
200 plc/3.33 s (4 s) 110 dB
3
100 plc/1.67 s (2 s) 105 dB
3
20 plc/334 ms (400 ms) 100 dB
3
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 0 dB
1
For 1 KΩ unbalance in LO lead
2
For power line frequency ±0.1%
3
For power line frequency ±1% use 80 dB or ±3% use 60 dB
4
Reading speeds for 60 Hz and (50 Hz) operation
5
For fixed function and range, readings to memory, scaling and alarms off, AZERO OFF
6
Maximum limit with default settling delays defeated
7
Speeds are for 4
1
/
2
digits, delay Ø, display off, autozero off, using 115 kbaud RS-232 setting
8
Isolation voltage (ch-ch, ch-earth) 300 Vdc, AC rms
9
6
1
/
2
digits = 22 bits, 5
1
/
2
digits = 18 bits, 4
1
/
2
digits = 15 bits
10
Assumes relative time format (time since start of scan)