Varian 990 dCLD II, Руководство по эксплуатации

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Model 990 dCLD II Component Leak Detector
3-21
3.7 Analog Leak Rate Output Voltage
To use the analog leak rate output voltage to measure leak rate, you must set the format of
the output voltage. The 990 dCLD II offers a choice of four leak rate output voltage formats
as shown in Table 3-2. The output voltage format is selected by entering the appropriate
command listed in Table 3-2, through the host serial port or, if the optional front control
panel is installed, through the Output Control Set-Up screen (see Section 4.6.5 “Output
Control Setup” on page 4-16).
Table 3-2 also shows the conversion formulas for each output. The last column of the table
references a graph to use for converting the output voltage to the leak rate for each output
option. These graphs are in Section 3.7.1 “Analog Leak Rate Output Voltage Conversion
Charts” on page 3-22.
Section 3.7.2 “Conversion of 2 V/Dec Log to Leak Rate if 10X Function Not Available” on
page 3-24 contains an explanation of the recommended output and conversion formula if
your PLC does not have a 10
x
function.
Table 3-2 Analog Leak Rate Voltage Outputs
Output
Option
Set-up
Command
Formula Output Response
Curve
Leak Rate Vout
Linear 0 - 10 V INIT-LINEAR<CR> Vout /
(10
|RANGE variable|
)
(Leak Rate) X
(10
|RANGE variable|
)
Figure 3-3 on
page 3-22
1 V/decade INIT-1LOG <CR> Leak Rate =
10
Vout
/
10
|RANGE variable| +3
LOG (Leak Rate X
10
|RANGE variable| +3
)
Figure 3-4 on
page 3-22
2 V/decade INIT-2LOG<CR> Leak Rate =
10
Vout/2
/
10
|RANGE variable| +3
2 X LOG (Leak Rate X
10
|RANGE va3
)
Figure 3-5 on
page 3-23
3 V/decade INIT-3LOG<CR> Leak Rate =
10
Vout/3
/
10
|RANGE variable| +3
3 X LOG (Leak Rate X
10
|RANGE variable| +3
)
Figure 3-6 on
page 3-23