Omron K7L-AT50 Liquid Leakage Sensor Amplifier

Technical Overview

The Omron K7L-AT50 is a high-sensitivity liquid leakage sensor amplifier designed for stable detection of various liquids, ranging from general water to liquid chemicals with low conductivity. It utilizes an inter-electrode resistance detection system with four selectable sensing ranges up to 50 MΩ. The compact unit supports up to 10m of sensing bands and 50m of connecting cable. It provides an NPN/PNP open-collector digital output for rapid integration into PLCs and control panels to prevent costly liquid damage in industrial environments.

Key Features

Four selectable sensing ranges (up to 50 MΩ) for diverse liquid conductivities [1.3].
Stable detection of impedance liquids and general water.
Built-in adjustable resistance threshold (ADJUST dial) for precise sensitivity control.
Selectable output operation (ON/OFF upon detection) via side-mounted DIP switches.
Supports long-distance wiring (up to 50m connecting cable and 10m sensing band).
NPN/PNP open-collector digital output (100 mA at 30 VDC max).

Technical Specification Matrix

Parameter	Value
Power Supply Voltage	12 to 24 VDC (Allowable range: 10 to 30 VDC)
Operate Resistance	0 to 50 MΩ, variable (Range 0: 0 to 250 kΩ; Range 1: 0 to 600 kΩ; Range 2: 0 to 5 MΩ; Range 3: 0 to 50 MΩ)
Output Configuration	Open-collector transistor output (100 mA at 30 VDC max)
Response Time	Operate: 800 ms max; Release: 800 ms max
Power Consumption	1 W max
Ambient Operating Temperature	-10°C to 55°C
Ambient Operating Humidity	45% to 85%
Max Wiring Distance (Connecting Cable)	50 m max
Max Sensing Band Length	10 m max
Dielectric Strength	1,000 VAC at 50/60 Hz for 1 min between case and current-carrying parts

Industrial Applications

1. Semiconductor Manufacturing Chemical Leak Detection

The K7L-AT50 detects aggressive chemical leakages in the drain pans beneath CMP (Chemical Mechanical Planarization) measuring baths. Its variable operate resistance accommodates low-conductivity liquid chemicals reliably, minimizing device damage and wafer irregularities.

Problem Solved

Prevents highly corrosive or low-conductivity processing chemicals from damaging sensitive semiconductor manufacturing equipment and contaminating cleanroom environments.

Low-conductivity liquidsOperate Resistance 50 MΩ12-24 VDCCleanroom leak detection

2. Server Room & Data Center Under-Floor Water Sensing

Utilizing its long wiring capabilities, the K7L-AT50 safely resides in a control panel while connecting to up to 10 meters of sensing bands under raised floors near CRAC (Computer Room Air Conditioning) units, instantly detecting condensation or coolant leaks.

Problem Solved

Unseen water leaks from precision cooling systems can cause catastrophic short circuits in high-value IT infrastructure under raised floors.

Wiring Distance 50mSensing Band 10mOpen-collector Output1W Power Consumption

3. Food and Beverage Processing Tank Monitoring

The amplifier monitors liquid ingress or spills around large food processing vats. With an 800 ms response time, the open-collector output signals the central PLC to actuate safety shut-off valves the moment a fluid leakage bridges the sensing band.

Problem Solved

Accidental liquid spills around industrial vats create dangerous slip hazards, risk bacterial growth, and cause equipment downtime.

Response Time 800msOpen-collector 100mANPN/PNP OutputAdjustable sensitivity