MKS PDR 2000 - Analog Output

Chapter Three: Operation
40
100 torr X.XX torr XX.X torr 0.01 torr 0.1 torr 0.2 torr 99.9 torr
20 torr XXX mtorr XX.X torr 1 mtorr 20 mtorr 40 mtorr 19.9 torr
10 torr XXX mtorr X.XX torr 1 mtorr 10 mtorr 20 mtorr 9.99 torr
2 torr XX.X torr X.XX torr 0.1 mtorr 2 mtorr 4.0 mtorr 1.99 torr
1 torr XX.X mtorr XXX mtorr 0.1 mtorr 1 mtorr 2.0 mtorr 999 mtorr
100 mtorr X.XX mtorr XX.X mtorr 0.01 mtorr 0.1 mtorr 0.2 mtorr 99.9 mtorr
50 mtorr X.XX mtorr XX.X mtorr 0.01 mtorr 0.05 mtorr 0.1 mtorr 49.9 mtorr
20 mtorr X.XX mtorr XX.X mtorr 0.01 mtorr 0.1 mtorr 0.04 mtorr 19.9 mtorr
Table 5: PDR 2000 Ranges: Sensor, High, Low, Set Points
Note
• From 100% of full scale to approximately 105% of full scale, the
display will flash.
• Above approximately 105% of full scale, the display will indicate
“OFF”.
• 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 PDR2000 zero and sensor zero will move
readings out of the negative range.
Analog Output
The analog output is calculated from the value of the digital display. 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 follow
because of normal tolerances in the electronics; there may be minor differences in the values you observe
compared to those shown.
Analog Output and Displayed Pressure
Displayed Pressure
Analog Output – volts
LO
0.00
0 mTorr (µBar) or less
0.00