Agilent Technologies 34970A, Руководство пользователя

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Chapter 4 Features and Functions
General Measurement Configuration
Custom A/D Integration Time
Integration time is the period of time that the instrument’s
analog-to-digital (A/D) converter samples the input signal for a
measurement. Integration time affects the measurement resolution (for
better resolution, use a longer integration time) and measurement speed
(for faster measurements, use a shorter integration time).
• Integration time is specified in number of power line cycles (PLCs).
Select from 0.02, 0.2, 1 , 2, 10, 20, 100, or 200 power line cycles.
The default is 1 PLC.
• Only the integral number of power line cycles (1, 2, 10, 20, 100, or 200
PLCs) provide normal mode (line frequency noise) rejection.
• You can also specify integration time directly in seconds (this is called
aperture time ). Select a value between 400 µs and 4 seconds, with
10 µs resolution.
• The only way to control the reading rate for AC measurements is by
changing the channel delay ( see page 105 ) or by setting the AC filter
to the highest frequency limit ( see page 131 ).
• The specified integration time is used for all measurements on the
selected channel. If you have applied Mx+B scaling or have assigned
alarms to the selected channel, those measurements are also made
using the specified integration time. Measurements taken during the
Monitor function also use the specified integration time.
• The following table shows the relationship between integration time,
measurement resolution, number of digits, and number of bits.
Integration Time Resolution Digits Bits
0.02 PLC
0.2 PLC
1 PLC
2 PLC
10 PLC
20 PLC
100 PLC
200 PLC
<0.0001 x Range
<0.00001 x Range
<0.000003 x Range
<0.0000022 x Range
<0.000001 x Range
<0.0000008 x Range
<0.0000003 x Range
<0.00000022 x Range
4½ Digits
5½ Digits
5½ Digits
6½ Digits
6½ Digits
6½ Digits
6½ Digits
6½ Digits
15
18
20
21
24
25
26
26
34970A Refresh UG.book Page 120 Wednesday, February 17, 2010 12:34 PM