Datasheet

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Medium
Fast
20 Hz - 300 kHz
200 Hz - 300 kHz
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, 10 kΩ 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
1 s, 100 ms, or 10 ms
Measurement timeout
Selectable 3 Hz, 20 Hz, 200 Hz LF limit
Measurement consideration (frequency and period): All frequency counters are susceptible to error when measuring low-
voltage, low-frequency signals. Shielding inputs from external noise pickup is critical for minimizing measurement errors.
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 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
1 A 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 > 5 kΩ
Thermistor
44004, 44007, 44006 series
RTD
a = 0.00385 (DIN) and a = 0.00392
Measurement noise rejection 60/50 Hz
1
DC CMRR
AC CMMR
140 dB
70 dB
Integration time Normal mode rejection
2
200 plc/3.33 s (4 s)
100 plc/1.67 s (2 s)
20 plc/333 ms (400 ms)
10 plc/167 ms (200 ms)
2 plc/33.3 ms (40 ms)
1 plc/16.7 ms (20 ms)
< 1 plc
105 dB
3
100 dB
3
95 dB
3
90 dB
3
85 dB
60 dB
0 dB
1. For 1 kΩ 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