Agilent Technologies 34970A, Руководство по обслуживанию, Страница: 21 / 273

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
Ω ±
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 Ω for 10 mA; 0.1 Ω 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.
AC Operating Characteristics
[4]
Function
ACV, ACI:
Digits
[5]
6
1
⁄
2
6
1 ⁄
2
6
1 ⁄
2
6
1
⁄
2
6 1
/2
Readings/s
7 sec/reading
1
8
[6]
10
100
[7]
AC Filter
Slow (3 Hz)
Medium (20 Hz)
Fast (200 Hz)
Fast (200 Hz)
Fast (200 Hz)
Single Channel Measurement Rates
[8]
Function
ACV:
Frequency, Period:
Resolution
6
1
⁄
2
Slow (3 Hz)
6
1
⁄
2
Medium (20 Hz)
6
1
⁄
2
Fast (200 Hz)
6 1
/2
[7]
6
1
⁄
2
Digits (1s gate)
5
1
⁄
2
Digits (100 ms)
4
1
⁄
2
Digits (10 ms)
Readings/s
0.14
1
8
100
1
9
70
[1] 300 Vrms isolation voltage (ch-ch, ch-earth)
[2] For frequencies below 100 Hz, slow AC filter specified for
sinewave input only
[3] For 1 k Ω unbalance in LO lead
[4] Maximum reading rates for 0.01% of ac step additional error.
Additional settling delay required when input dc level varies.
[5] 6
1
⁄
2
digits=22 bits, 5
1
⁄
2
digits=18 bits, 4
1
⁄
2
digits=15 bits
[6] For external trigger or remote operation using default
settling delay (Delay Auto)
[7] Maximum limit with default settling delays defeated
[8] For fixed function and range, readings to memory,
scaling and alarms turned off
1
Chapter 1 Specifications
AC Measurement and Operating Characteristics
19