Chapter 4 Features and Functions

General Measurement Configuration

W>X c

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 x vvx(PLCs). Select from 0.02, 0.2, B, 2, 10, 20, 100, or 200 power line cycles. g“x wxyt 8 cYO5

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 txx x

). Select a value between 400 μs and 4 seconds,

 

 

with 10 μs resolution.

4

For temperature measurements, the integration time is fixed at

 

1 PLC.

∙ The only way to control the reading rate for ac measurements is by changing the channel delay (x tzx DD ) or by setting the ac filter to the highest frequency limit (x tzx 88= ).

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

< 0.0001 x Range

412 Digits

15

0.2 PLC

< 0.00001 x Range

512 Digits

18

1 PLC

< 0.000003 x Range

512 Digits

20

2 PLC

< 0.0000022 x Range

612 Digits

21

10 PLC

< 0.000001 x Range

612

Digits

24

20 PLC

< 0.0000008 x Range

612

Digits

25

100 PLC

< 0.0000003 x Range

612

Digits

26

200 PLC

< 0.00000022 x Range

612

Digits

26

 

 

 

 

 

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Image 102
HP 34970A manual WX c, Integration Time Resolution Digits Bits