DUNIWAY Stockroom Terranova 908A, Инструкция по эксплуатации

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D U N I W A Y S T O C K R O O M C O R P .
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M. Reading Pressure
Pressure display and ranging are automatic in the 908A. Most readings will take place between
zero pressure and the full scale of the 908A. The following table will help explain operation:
Sensor
Range
Full-
Scale
908A
Lowest
Scale
908A
Highest
Scale
Highest
Display
Resolution
Lowest
Recommended
Reliable Value
Lowest
Set Point
Highest
Set
Point
10 ktorr X torr XXE3 torr 1 torr 5 torr 50 torr 9990 torr
1000 torr X.X torr XXXX torr 0.1 torr 0.5 torr 5 torr 999.0 torr
100 torr X.XX torr XXX.X torr 0.01 torr 50 mtorr 0.50 torr 99.90 torr
20 torr X.XXX torr XX.XX torr 1 mtorr 10 mtorr 100 mtorr 19.98 torr
10 torr X.XXX torr XX.XX torr 1 mtorr 5 mtorr 50 mtorr 9.990 torr
2 torr X.X mtorr X.XXX torr 0.1 mtorr 1 mtorr 10 mtorr 1.998 torr
1 torr X.X mtorr X.XXX torr 0.1 mtorr 0.5 mtorr 5 mtorr 999.0 mtorr
100 mtorr X.XX mtorr XX.XX mtorr 0.01 mtorr 0.05 mtorr 0.5 mtorr 99.90 mtorr
50 mtorr X.XX mtorr XX.XX mtorr 0.01 mtorr 0.025 mtorr 0.25 mtorr 49.95 mtorr
20 mtorr X.XX mtorr XX.XX mtorr 0.01 mtorr 0.01mtorr 0.1 mtorr 19.90 mtorr
Notes:
1. From 100% of full scale to approximately 130% of full scale, the display will flash.
2. Above approximately 130% of full scale, the display will indicate
“HI”.
3. Prior to proper setting of zero, the display may show a negative value, as low as –1% of full scale.
Of course negative readings are meaningless, but only provide span for adjustment.
Below approximately –1% of full scale, the display will indicate
“LO”.
Proper adjustment of the 908A zero and sensor zero will move readings out of the negative range.
Figure 12: 908A Ranges: Sensor, High, Low, Set Points
N. Analog Output
The analog output is calculated from the value of the digital display and for the gauge selected.
The output is logarithmic, 0.5 volt/decade; the source impedance for the output is 1 K ohm. The
output voltage is calculated from:
V=0.50*(log
10
(100*Pressure))
where V is the Analog Output in volts; P is the pressure in mTorr or µbar. Some examples fol-
low; because of normal tolerances in the electronics, there may be minor differences in the values
you observe compared to those shown:
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