The WLI capacitive sensor probe is a non-conductive probe that determines the level of liquid in a tank by measuring the change in frequency due to the change of capacitance across the probes the liquid changes height. This is accomplished by using the probes as the plates of a capacitor and the liquid as the insulator between the plates. The probe is calibrated to the dielectric constant of water. The probe is also sealed against the environment in order to insure long life and accurate performance. WLI Series is designed as a level indicator onlyand should not be used as a level controller. WLI Series can be usedin conjunction with WLC units.The can be used in place of any Ultrasound Level Indicator, especially in water where there can sometimes be technical issues with the Ultrasound technology. The output is a 0 to 20 mA signal that can drive a resistance up to 1100 Ohms. The input voltage required is 24 VDC. By using a current output, the output becomes immune to interference from outside sources. The output accuracy is stepped in 5% increments over the length of the probe and is accurate by plus or minus 10% over the length of the sensor.

Level Indicator

The WLI is a digital Liquid Level Indicator, Water Level Indicator and Water Level Indicator For Tank level indicators. It is a digital capacitance level indicator with the ability to field calibrate for the type of liquid. Knowing the water level in a tank can be valuable information in Well Water Holding Tanks, Wastewater Treatment facilities or other water tank level indicator needs. This new advanced Water Level indicator Technology replaces ultrasonic sensor systems as well as float switches. CheckPoint is not designed to be a level controller since its accuracy is between 5% & 10%. If you need a water level controller try one of the WLC Series Level Controls.

The liquid level indicators are guaranteed trouble-free digital technology liquid level indicators. These water level indicators will eliminate the hassle and frustration normally associated with existing float switches, ultrasonic or other electric level indicators.

The probes can be built in any length needed for your water level indicator needs or other applications. Both models have a field calibration system built in that is set by using a magnet to reset a reed switch in the controls – Simple and fast for your liquid level indicator needs. And while we feel the sturdy construction of our components, like the water level indicators, will result in the water level control system out-lasting the waste water treatment environment, the advanced modular design of each unit allows easy replacement of individual parts instead of requiring replacement of the entire unit unlike the float switch or current OEM liquid level indicator systems, which could requires a complete replacement.

We make custom probes to fit any application. All sensor rod tips are threaded so Extension Kits can be added if needed.


All of our liquid level controls and liquid level sensors are assembled right here in the U.S.A.
where we monitor every step of the process.


We offer products comparable to the products offered by the above companies. See our website pages for further information on the products. The tradenames and trademarks in this page are owned by their respective companies or are the same name as the company. They are mentioned for comparison purposes only. They are in no way affiliated with System Dynamics, Inc or WaterLine Controls.