User`s guide

329
Chapter 8 Specifications
AC Measurement and Operating Characteristics
4
8
AC Measurement and Operating Characteristics
AC Measurement Characteristics
[1]
True RMS AC Voltage
Measurement Method:
Crest Factor:
Additional Crest Factor
Errors (non-sinewave):
[2]
AC Filter Bandwidth:
Slow
Medium
Fast
Input Impedance:
Input Protection:
AC-coupled True RMS -measures
the AC component of input with up to
300 VDC of bias on any range
Maximum 5:1 at Full Scale
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
3 Hz - 300 kHz
20 Hz - 300 kHz
200 Hz - 300 kHz
1 M ±2%, in parallel with 150 pF
300 Vrms on all ranges
Frequency and Period
Measurement Method:
Voltage Ranges:
Gate Time:
Measurement Timeout:
Reciprocal counting technique
Same as AC Voltage function
1s, 100 ms, or 10 ms
Selectable 3 Hz, 20 Hz, 200 Hz LF
limit
True RMS AC Current
Measurement Method:
Shunt Resistance:
Input Protection:
Direct coupled to the fuse and shunt.
AC-coupled True RMS
measurement (measures the AC
component only)
5 for 10 mA; 0.1 for 100 mA, 1A
1.5A 250 V fuse on 34901A module
Measurement Noise Rejection
[3]
AC CMRR: 70 dB
Measurement Considerations (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.
34970A Refresh UG.book Page 329 Wednesday, February 17, 2010 12:34 PM