Honeywell W7761A - 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.