1811D INSTRUCTION MANUAL
56-101-00164 Rev. F
SECTION 3
Apr / 19 / 13
Page 25 of 38
(4) Open the PRESSURE (#1) valve gradually. Set up the desired airspeed value for
the equivalent pressure. (Refer to Table 4 below.)
Airspeed
Inches
Water
Inches
Mercury
Pounds
Sq. In.
Airspeed
Inches
Water
Inches
Mercury
Pounds
Sq. In.
39 1.000
0.073
0.036 285
55.416
4.072
2.000
55 2.000
0.146
0.072 314
68.045
5.000
2.466
68 3.000
0.220
0.108 342
81.654
6.000
2.947
78 4.000
0.294
0.144 355
83.124
6.108
3.000
87 5.000
0.367
0.180 368
95.263
7.000
3.438
96 6.000
0.441
0.216 391
108.872
8.000
3.929
103 7.000
0.514
0.252
395
110.832
8.144 4.000
110 8.000
0.587
0.289
413
122.481
9.000 4.420
117 9.000
0.661
0.325
433
136.090
10.000
4.912
123 10.000
0.734
0.361
437 138.540
10.180 5.000
135 12.000
0.881
0.433
470 163.308
12.000 5.894
144 13.609
1.000
0.481
474 166.248
12.216 6.000
146 14.000
1.028
0.505
504 190.526
14.000 6.876
155 16.000
1.175
0.577
508 193.955
14.252 7.000
165 18.000
1.322
0.649
534 217.744
16.000 7.859
174 20.000
1.468
0.721
538 221.663
16.288 8.000
194 25.000
1.836
0.901
561 244.962
18.000 8.841
203 27.218
2.000
0.982
565 249.371
18.324 9.000
204 27.707
2.036
1.000
587 272.180
20.000 9.823
212 30.000
2.202
1.082
591 277.079
20.360
10.000
229 35.000
2.570
1.262
611 299.398
22.000
10.806
244 40.000
2.937
1.443
615 304.787
22.396
11.000
246 40.827
3.000
1.473
633 326.616
24.000
11.788
258 45.000
3.304
1.623
638 332.495
24.432
12.000
271 50.000
3.671
1.803
644 340.225
25.003
12.279
283 54.436
4.000
1.965
Airspeed Equivalent (knots) for Differential Pressure / Vacuum
Table 4
Note: To lower the airspeed reading or to return the system to ambient, gradually open
the PRESSURE VENT (#2) valve.