Log 1-8; Log-Linear Analog Output Equation & Table - Torr - Instrutech VGC301 User Manual

Instruction Manual
7.1 Log 1-8; Log-Linear Analog Output Equation & Table - Torr
Log-Linear 1 to 8 V analog output for selected gases - Engineering units in Torr
True Pressure
N
2
(Torr)
0.0001 1.000
0.0002 1.301
0.0005 1.699
0.0010 2.000
0.0020 2.301
0.0050 2.699
0.0100 3.000
0.0200 3.301
0.0500 3.699
0.1000 4.000
0.2000 4.301
0.5000 4.699
1.0000 5.000
2.0000 5.301
5.0000 5.699
10.0000 6.000
20.0000 6.301
50.0000 6.699
100.0000 7.000
200.0000 7.301
300.0000 7.477
400.0000 7.602
500.0000 7.699
600.0000 7.778
700.0000 7.845
760.0000 7.881
800.0000 7.903
900.0000 7.954
1000.0000 8.000
The log-linear output signal and pressure are related by the following formulas:
P = 10
where P is the pressure in torr, and V is the output signal in volts.
An analog output of 10 volts indicates a faulty convection gauge or unplugged gauge cable.
The chart on the following page shows the graphical results of the table and formulas given above for nitrogen.
True pressure (N ) is plotted on the X-axis with a log scale. The output signal is plotted on the Y-axis on a linear
2
scale.
Note - when using the units of pascals and LOG 1-8 is selected , the same equation of P = 10
applies. This results in a log-linear analog output range of 1 to 10.12 Vdc for 1.30E-02 pascals to 133 kpa.
InstruTech, Inc.
O
Ar He
2
1.000 1.000 1.000
1.301 1.301 1.301
1.699 1.699 1.699
1.845 1.903 2.000
2.146 2.204 2.301
2.519 2.602 2.699
2.820 2.908 2.987
3.117 3.207 3.297
3.511 3.607 3.692
3.808 3.914 3.988
4.100 4.217 4.288
4.494 4.638 4.687
4.778 4.973 4.987
5.057 5.346 5.288
5.389 6.130 5.697
5.602 8.041 6.013
5.763 8.041 6.348
5.895 8.041 6.890
5.946 8.041 7.320
5.991 8.041 7.470
6.053 8.041 7.580
6.130 8.041 7.686
6.207 8.041 7.781
6.274 8.041 7.863
6.338 8.041 7.934
6.375 8.041 7.974
6.400 8.041 7.999
6.455 8.041 8.041
6.512 8.041 8.041
Values listed under each gas type are in volts.
(V - 5)
V = log (P) + 5
10
CO
Kr Freon12
2
1.000 1.000 1.000
1.301 1.301 1.301
1.699 1.477 1.699
2.041 1.602 2.176
2.362 2.000 2.491
2.643 2.362 2.881
3.041 2.681 3.167
3.346 2.978 3.476
3.740 3.371 3.860
4.029 3.670 4.155
4.322 3.960 4.439
4.689 4.336 4.786
4.978 4.602 5.021
5.233 4.845 5.210
5.524 5.107 5.389
5.696 5.250 5.471
5.819 5.360 5.521
5.915 5.410 5.579
5.966 5.438 5.670
6.090 5.521 5.777
6.228 5.555 5.838
6.350 5.595 5.883
6.458 5.624 5.918
6.561 5.647 5.947
6.664 5.667 5.974
6.732 5.677 5.989
6.774 5.685 5.998
6.900 5.698 6.021
7.045 5.706 6.045
VGC301 Controller
D
Freon22 Ne
2
1.000 1.000 1.000
1.301 1.301 1.301
1.699 1.699 1.699
2.176 2.114 1.845
2.491 2.380 2.176
2.845 2.778 2.544
3.130 3.083 2.851
3.435 3.386 3.149
3.839 3.778 3.542
4.134 4.083 3.845
4.418 4.398 4.149
4.774 4.837 4.555
5.017 5.190 4.872
5.220 5.616 5.201
5.418 7.391 5.719
5.530 8.041 6.332
5.571 8.041 7.766
5.617 8.041 8.041
5.691 8.041 8.041
5.808 8.041 8.041
5.876 8.041 8.041
5.925 8.041 8.041
5.964 8.041 8.041
5.998 8.041 8.041
6.029 8.041 8.041
6.045 8.041 8.041
6.057 8.041 8.041
6.079 8.041 8.041
6.104 8.041 8.041
(V - 5)
CH
4
1.000
1.301
1.699
2.230
2.519
2.886
3.185
3.483
3.888
4.201
4.498
4.893
5.204
5.522
5.877
6.446
7.550
7.925
8.041
8.041
8.041
8.041
8.041
8.041
8.041
8.041
8.041
8.041
8.041
listed above
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