Atec Agilent-34980A - Manual (Page 22)

22
Measurement characteristics with
optional internal DMM
DC voltage
Measurement method Continuously integrating multi-slope
III A-D converter
A-D linearity 0.0002% of reading + 0.0001% of
range on 10 V range
Input resistance
100 mV, 1 V, 10 V ranges
Selectable 10 M Ω or > 10,000 M Ω
100 V, 300 V ranges 10 M Ω ± 1%
Input bias current < 50 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 M Ω ± 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, 1k Ω,
10k Ω ranges
Maximum lead resistance 10% of range per lead for 100 Ω
and 1k Ω ranges. 1k Ω 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 1s, 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 1A 250 V fuse on 34921A module
True RMS AC current
Measurement method Direct coupled to the fuse and shunt.
AC coupled True RMS measurement
(measures the ac component only)
Shunt resistance 5 Ω for 10 mA; 0.1 Ω for 100 mA, 1 A
Input protection 1A 250 V fuse on 34921A module
Thermocouple
Conversion ITS-90 software compensation
Reference junction type Internal, fixed, or external
Open thermocouple check Selectable per channel. Open > 5k Ω
Thermistor 44004, 44007, 44006 series
RTD a = 0.00385 (DIN) and a = 0.00392
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) 105 dB
[3]
100 plc/1.67 s (2 s) 100 dB
[3]
20 plc/333 ms (400 ms) 95 dB
[3]
10 plc/167 ms (200 ms) 90 dB
[3]
2 plc/33.3 ms (40 ms) 85 dB
1 plc/16.7 ms (20 ms) 60 dB
< 1 plc 0 dB
DC CMRR 140 dB
AC CMRR 70 dB
[1] For 1 K Ω unbalance in LO lead
[2] For power line frequency ± 0.08%
[3] For power line frequency ± 1% use 75 dB or ± 2.5% 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, autozero off
[6] Maximum limit with default settling delays defeated
[7] Speeds are for 4 1 ⁄
2
digits, delay Ø, display off, autozero off
[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)