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K7L-AT50[] / AT50D[]

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.
Weight Approx. 14 g


Rated power
supply voltage
12 to 24 VDC (Allowable voltage fluctuation range: 10 to 30 VDC)
0 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 Settings.) 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
With any range, resistance values can be set from 0 Ω.
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
NPN 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.)
Accessories Terminal Block Screwdriver for ADJUST Terminator
K7L-AT50/AT50B 1 1 ---
K7L-AT50D/AT50DB 1 1 1
K7L-AT50D-S 1 1 ---

* For the K7L-AT50D.