Ulvac GI-M2 - Pseudo-LOG Output

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9.6.4. Pseudo-LOG output
The entire measurable pressure range is outputted pseudo-logarithmically by an analog
voltage of 0 to 10 volts. The output voltage has hysteresis by the pressure that increased
and the pressure that decreased.
The table below gives the relationship between pressure and output voltage.
GI-M2 Pseudo-LOG OUTPUT
Table. 9-3 Measured Pressure Value Table (GI-M2)
Displayed pressure
value (Pa)
Output voltage
(V)
Displayed pressure
value (Pa)
Output voltage
(V)
9.90
×
10
-0
8.99
1.00
×
10
-4
4.10
1.00
×
10
-0
8.10
5.00
×
10
-5
3.50
5.00
×
10
-1
7.50
1.00
×
10
-5
3.10
1.00
×
10
-1
7.10
5.00
×
10
-6
2.50
5.00
×
10
-2
6.50
1.00
×
10
-6
2.10
1.00
×
10
-2
6.10
5.00
×
10
-7
1.50
5.00
×
10
-3
5.50
1.00
×
10
-7
1.10
1.00
×
10
-3
5.10
5.00
×
10
-8
0.50
Displayed pressure
value (Torr)
Output voltage
(V)
Displayed pressure
value (Torr)
Output voltage
(V)
5.00
×
10
-2
8.99
1.00
×
10
-6
4.10
1.00
×
10
-2
8.10
5.00
×
10
-7
3.50
5.00
×
10
-3
7.50
1.00
×
10
-7
3.10
1.00
×
10
-3
7.10
5.00
×
10
-8
2.50
5.00
×
10
-4
6.50
1.00
×
10
-8
2.10
1.00
×
10
-4
6.10
5.00
×
10
-9
1.50
5.00
×
10
-5
5.50
1.00
×
10
-9
1.10
1.00
×
10
-5
5.10
5.00
×
10
-10
0.50
Table. 9-4 Hysteresis by the pressure that increased and decreased
Increae
Decrease
Displayed pressure
value (Pa)
Output voltage
(V)
Displayed pressure
value (Pa)
Output voltage
(V)
1.00
×
10
-1
7.10
1.00
×
10
-1
7.10
0.90
×
10
-1
7.09
9.00
×
10
-2
6.90
0.80
×
10
-1
7.80
8.00
×
10
-2
6.80
The measurement output voltage can be converted to a pressure value using the following
equation.
P:Pressure value （Pa）
V:Measured output voltage （V）
E:V from which decimal point is rounded down （V）
GI-M2:
P=10(V-E)×10
-(
８
-E)
（Pa）