Product Category

Liquid Leakage Sensor Amplifier/Liquid Leakage Sensor Amplifier with Disconnection Detection Function

K7L-AT50[] / AT50D[][]

Reliable Detection of a Wide Variety of Liquids Ranging from Water to Liquid Chemicals with Low Conductivity. Four Sensing Ranges Available. K7L-AT50B and K7L-AT50DB are our Value Design products which increase the value of your control panels.


Ambient temperature

Operating: -10 to +55°C

Ambient humidity

Operating: 45% to 85%

Insulation resistance

10 MΩ at 100 VDC between case and current-carrying parts

Dielectric strength

1,000 VAC at 50/60 Hz for 1 min between case and current-carrying parts

Power consumption

1 W max.

Response time

Operate:800 ms max.
 Release:800 ms max.
 When turning ON power: 2 s max.


Approx. 14 g


Rated power supply

12 to 24 VDC (Allowable voltage fluctuation range: 10 to 30 VDC)

Operate resistance

Ω to 50 MΩ, variable
 Range 0: 0 to 250 kΩ. Range 1: 0 to 600 kΩ
 Range 2: 0 to 5 kΩ. Range 3: 0 to 50 kΩ
 The range is set using the DIP switch on the side of the Sensor Amplifier. (Refer to DIP Switch
 Set the corresponding pin of the DIP switch in the up position. (For range 0, set all 3 pins in the
 down position.) The adjuster (ADJUST) on the top of the Sensor Amplifier sets the resistance
 value for detection within the set range. It is factory-set to the upper limit. (Normally, the K7L
 can be used with the adjuster at this setting.) With any range, resistance values can be set from
 0 Ω.

 detection function

Detection signal: 10 VDC max., 200 ms
 Detection time: 10 s max.
 Recovery: Operation is recovered by resetting the power supply.

Release resistance

105% min. of operate resistance


Open-collector transistor output with 100 mA at 30 VDC max. for both liquid leakage detection
 and disconnection detection.
 Max. 30 VDC, 100mA
 If the rightmost pin of the DIP switch on the side of the Sensor Amplifier is set to the down
 position, the output turns ON when liquid is detected; if it is set to the up position, the output
 turns OFF when liquid is detected.

Wiring distance

Connecting cable: 50 m max.
 Sensing Band length: 10 m max.
 These values are possible on condition that a completely insulated 3-conductor VCT cable with a
thickness of 0.75 mm2 and a dielectric strength of 600 V is used together with a Liquid Sensing
Band specified by OMRON. (A 0.2-mm2 cable can also be used.)


Terminal Block

Screwdriver for ADJUST














* For the K7L-AT50D[][].