120
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
Summary of Contents for 34970A
Page 16: ...16 34970A Refresh UG book Page 16 Wednesday February 17 2010 12 34 PM ...
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Page 21: ...1 1 Quick Start 34970A Refresh UG book Page 21 Wednesday February 17 2010 12 34 PM ...
Page 39: ...2 2 Front Panel Overview 34970A Refresh UG book Page 39 Wednesday February 17 2010 12 34 PM ...
Page 59: ...3 3 System Overview 34970A Refresh UG book Page 59 Wednesday February 17 2010 12 34 PM ...
Page 87: ...4 4 Features and Functions 34970A Refresh UG book Page 87 Wednesday February 17 2010 12 34 PM ...
Page 217: ...5 5 Error Messages 34970A Refresh UG book Page 217 Wednesday February 17 2010 12 34 PM ...
Page 241: ...6 6 Application Programs 34970A Refresh UG book Page 241 Wednesday February 17 2010 12 34 PM ...
Page 254: ...254 34970A Refresh UG book Page 254 Wednesday February 17 2010 12 34 PM ...
Page 255: ...7 7 Tutorial 34970A Refresh UG book Page 255 Wednesday February 17 2010 12 34 PM ...
Page 324: ...324 34970A Refresh UG book Page 324 Wednesday February 17 2010 12 34 PM ...