Hydrocarbon Liquid Sensor with Water 
Indicator 
OPW P/Ns: 6 feet: 30-0234-HW-06; 15 feet: 30-0234-HW-15;  
20 feet: 30-0234-HW-20 
   
Hydrocarbon Liquid Sensor Installation 
The Hydrocarbon Liquid/Water, which is available in lengths of 6 feet 
(1.8 m), 15 feet  (4.6 m) and 20  feet (6.1 m), is  used primarily for 
monitoring wet wells with fluctuating groundwater tables. The sensor 
contains a carbon/polymer material that changes its resistance when 
exposed  to  liquid  hydrocarbons.  Additionally,  a  water  sensor  that 
relies on the conductivity of water to detect its presence is utilized, 
providing the ability to discriminate between hydrocarbon liquid and 
water. An alarm condition will result from the absence of groundwater 
in a monitoring well. Detection of fuel entering the containment area 
(indicating a leak) will also result in an alarm condition, as will a break 
in the cable or sensor malfunction. 
*NOTE: Maximum Wiring Length is the maximum length of cable to 
be used to connect all sensors on an individual channel. This length 
includes run of cable from I.S. Barrier to each sensor board in the 
string. 
 
 
Uncontaminated: 1,000 – 3,000 ohms/ft 
Contaminated: 30,000 - 200,000 ohms/ft