Honeywell W7761A User Manual
Page 77
EXCEL 10 W7761A INPUT/OUTPUT DEVICE
77
74-2699
Fig. E-6. Graph of Sensor Current versus Enthalpy (volts).
See Fig. E-7 for a partial psychometric chart for the a C7400A Solid State Enthalpy Sensor.
CONTROL
CURVE
A
B
C
D
CONTROL POINT
APPROX.
°
F (
°
C)
AT 50% RH
73 (23)
70 (21)
67 (19)
63 (17)
12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
44 46
90
100
80
70
60
50
40
30
20
10
ENTHALPY—BTU PER POUND DRY AIR
85
(29)
90
(32)
95
(35)
100
(38)
105
(41)
110
(43)
35
(2)
35
(2)
40
(4)
40
(4)
105
(41)
110
(43)
45
(7)
45
(7)
50
(10)
50
(10)
55
(13)
55
(13)
60
(16)
60
(16)
65
(18)
65
(18)
70
(21)
70
(21)
75
(24)
75
(24)
80
(27)
80
(27)
85
(29)
90
(32)
95
(35)
100
(38)
APPROXIMATE DRY BULB TEMPERATURE—
°
F (
°
C)
A
A
B
B
C
C
D
D
M11160
RELATIVE HUMIDITY (%)
1
1
HIGH LIMIT CURVE FOR W6210D,W7210D.
Fig. E-7. Partial psychometric chart for a C7400A Solid State Enthalpy Sensor.
See Fig. E-8 for a C7400A Solid State Enthalpy Sensor output current versus relative humidity.
20
10
30
40
50
60
70
80
90
100
60
50
40
70
80
90
100
PERCENT RH
TEMPERATURE
°
F (
°
C)
M11605
C7400A OUTPUT CURRENT
4 mA
6 mA
8 mA
10 mA
20 mA 18 mA 16 mA 14 mA 12 mA
(4)
(10)
(16)
(21)
(27)
(32)
(38)
D C
B
A
D = 17 MA
C = 15.5 MA
B = 13.5 MA
A = 11 MA
Fig. E-8. C7400A Solid State Enthalpy Sensor output current vs. relative humidity.