Submersible cable is more expensive because it has to be reinforced to support the sensor plus its own weight in deep holes without stretching which would lead to a change in sensor position and ultimately sensor calibration.
A submersible cable also has a vent tube running through it to allow gauge reference level transmitters to breath to ambient air pressure which is essential for accurate level measurement. Due to this extra complexity, submersible cable are more expensive than general purpose sensor cable and therefore the KL1 junction box helps reduce the cost of installations whilst providing a vent which prevents moisture ingress down the cable.
Although most instruments are not able to survive a direct lightning strike it is possible to protect nearby instrumentation from voltage surges which are less severe but can be just as damaging to sensitive sensor electronics without adequate discharge protection. The KL1 submersibe sensor junction box includes the option for protection from a 10 kiloamp discharge current.
If a PT100 temperature sensor probe is included in the installation the KL1 terminal box can include an option for a PT100 transmitter to convert the output from a platinum resistance thermometer to a 2 wire, 4 to 20 mA output signal.