tekmar 072 10k Slab Sensor - Manual

072_D
11/12 10k Slab Sensor 072
- Data Brochure
1 of 2 © 2012 072_D - 11/12
Replaces: 06/10
Sensor Wiring
Installation
A good quality test meter capable of measuring up to 5,000
kΩ (1 kΩ = 1000Ω) 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 on the
following page, estimate 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.
Caution: Do not run sensor wires parallel to telephone or
power cables. If sensor wires are located in an area with
strong sources of electromagnetic interference, shielded
cable or twisted pair should be used. Alternately, the
wires can be run in a metal conduit that is grounded to
the common sensor terminal on the control and not to
earth ground.
Sensor wiring can extended up to 500’ using 18
AWG wire.
Wire splices should be properly soldered and
protected in an accessible, waterproof junction box. •
•
Sensor Testing Instructions
The tekmar Slab Sensor 072 has a black high density
polyethylene head and is ideal for use in soil or concrete. The 072 is supplied with 20’ (6 m) of 2-conductor cable.
Slab Sensor 072 placed 1/2 way between the pipes
or cables inside the conduit
1”
(25 mm)
Note: Proper placement of sensors is critical for correct
control operation.
Though sensors are designed for direct embedding in
slab material, it is recommended to install them in a metal
or plastic sleeve. This allows for easy replacement if the
sensor should ever fail or have to be relocated. The sensor
should be placed 1” (25 mm) below the slab surface and
1/2 way between the pipes or electric cables.
Installing the Sensors
Slab Sensor 072