Rosemount Temperature Sensors and Accessories - Transcat

Sensors and Accessories (English)
Product Data Sheet
00813-0100-2654, Rev GB
April 2010
SPRING-LOADED SENSOR DIMENSIONS
When a spring-loaded sensor is used properly, the spring should be compressed approximately 1 /2-inch. Therefore, all measurements of
spring-loaded sensors are made with the spring compressed. If you measure an existing spring-loaded sensor while it is in a relaxed state, you
must subtract 1 /2-inch to arrive at the installed length (X) that must be ordered. See Figure 1.
FIGURE 1. Spring Loaded Sensors Dimensions
Compressed Spring Loaded Sensor
3.45 (88)
Max.
Installed (X) Length
[Spring Compressed
0.5 (13) nominal]
0.5
Spring loaded sensor in a compressed state: The actual sensor length is measured when the spring is compressed approximately 1 /2-in.
shorter than the relaxed sensor.
Relaxed Spring Loaded Sensor
2.95 (88) Max.
Installed (X) Length + 0.5 in.
Spring loaded sensor in a relaxed state: Normally, when a spring loaded sensor is measured, it is in a relaxed state. You must subtract 1 /2-in.
from your measurement to order a replacement sensor. Rosemount Inc. assumes that the sensor length you specify is that of a compressed
sensor.
Determining the Length (L) of a spring-loaded sensor
to be used with an existing non-Rosemount
Thermowell
See Figure 1, Figure 3, and Figure 4.
1. Remove the existing generic sensor from the installed thermowell. Length Code Key
2. Measure the sensor length with the spring in the relaxed state (as shown in
L Thermowell length minus 0.25 in.
Figure 1). Measure from the tip of the sensor to the maximum thread engagement U Immersion length into process
point (0.53 in. into the threads).
T Lagging length
3. Subtract 0.5 inches from your measurement. The resulting length is (X). E Extension fitting length
4. If the sensor is installed with an extension, measure the extension length (E), as X Sensor length
shown in Figure 4. If the sensor is not installed with an extension, let (E) = 0.
Use the following equations to determine
all lengths
5. Since (X) = (E) + (L), subtract (E) from (X) to find (L).
Use the resulting length (L) in the Section 2 ordering tables to choose the correct length
of sensor.
L = U + T + 1.5
X = E + L
X = E + U + T + 1.5
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