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Mounting the Universal Sensor ----------------------- ------------- ------------------------------- -- --- -
Note: These sensors are designed to mount on a pipe or in a temperature
immersion well.
The Universal Sensor should be placed downstream of a pump or after an elbow
or similar fitting. This is especially important if large diameter pipes are used as
the thermal stratification within the pipe can result in erroneous sensor readings.
Proper sensor location requires that the fluid is thoroughly mixed within the pipe
before it reaches the sensor.
Strapped to Pipe
The Universal Sensor can be strapped directly to the pipe using the cable tie
provided. Insulation should be placed around the sensor to reduce the effect of
air currents on the sensor measurement.
Immersion Well
If a Universal Sensor is mounted onto 1" (25 mm) diameter L type copper pipe,
there is approximately an 8 second delay between a sudden change in water
temperature and the time the sensor measures the temperature change. This
delay increases considerably when mild steel (black iron) pipe is used. In general,
it is recommended that a temperature well be used for steel pipe of diameter
greater than 1-1/4" (32 mm). Temperature wells are also recommended when
large diameter pipes are used and fluid stratification is present.
Conduit Connection
The Universal Sensor and Universal Sensor Enclosure 080 (sold separately) are
specifically designed to mount onto a 3/8" (10 mm) ID temperature well that is
supplied with an end groove. To install the well, plumb a 'T' into the pipe and fix
the well into the 'T'. The 080 enclosure has a 7/8" (22 mm) back knockout that
must be removed and fitted over the temperature well. The universal sensor is
then inserted into the well and the retaining clip supplied with the enclosure is
snapped onto the well end groove. If the well has a threaded end, the installer
must supply a standard threaded conduit retaining ring. The two wires from the
sensor are connected to the terminal block provided in the enclosure. The other
side of the terminal block is used to connect wires from the control.
Testing the Sensor Wiring
A good quality test meter capable of measuring up to 5,000 kΩ
(1 kΩ = 1000 Ω) is required to measure the sensor resistance. In
addition to this, the actual temperature must be measured with
either a good quality digital thermometer, or if a thermometer
is not available, a second sensor can be placed alongside
the one to be tested and the readings compared.
First measure the temperature using the thermometer and
then measure the resistance of the sensor at the control. The
wires from the sensor must not be connected to the control
while the test is performed. Using the chart below, estimate
Temperature
Resistance
°F
°C
-50
-46
490,813
-45
-43
405,710
-40
-40
336,606
-35
-37
280,279
-30
-34
234,196
-25
-32
196,358
-20
-29
165,180
-15
-26
139,403
-10
-23
118,018
-5
-21
100,221
0
-18
85,362
5
-15
72,918
10
-12
62,465
15
-9
53,658
© 2011
D 406 - 12/11
-------------------------------------------------------------------------
Temperature
Resistance
°F
°C
20
-7
46,218
25
-4
39,913
30
-1
34,558
35
2
29,996
40
4
26,099
45
7
22,763
50
10
19,900
55
13
17,436
60
16
15,311
65
18
13,474
70
21
11,883
75
24
10,501
80
27
9,299
85
29
8,250
Retaining
Clip
the temperature measured by the sensor. The sensor and
thermometer readings should be close. If the test meter reads
a very high resistance, there may be a broken wire, a poor
wiring connection or a defective sensor. If the resistance is
very low, the wiring may be shorted, there may be moisture
in the sensor or the sensor may be defective. To test for
a defective sensor, measure the resistance directly at the
sensor location.
Do not apply voltage to a sensor at any time as damage
to the sensor may result.
Temperature
Resistance
°F
°C
90
32
7,334
95
35
6,532
100
38
5,828
105
41
5,210
110
43
4,665
115
46
4,184
120
49
3,760
125
52
3,383
130
54
3,050
135
57
2,754
140
60
2,490
145
63
2,255
150
66
2,045
155
68
1,857
8 of 48
Universal
Sensor
Sensor Well
Bottom of
Enclosure 080
Universal
Cable Tie
Sensor
Temperature
Resistance
°F
°C
160
71
1,689
165
74
1,538
170
77
1,403
175
79
1,281
180
82
1,172
185
85
1,073
190
88
983
195
91
903
200
93
829
205
96
763
210
99
703
215
102
648
220
104
598
225
107
553
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