Greyline ultrasonic sensors are mounted at the top of a tank or in a position above the liquid being measured. The sensor continuously transmits pulses of high frequency sound (typically 42 kHz) which travel away from the sensor, hit the surface of the liquid and return to the sensor.
The instrument electronics measure the time it takes from transmitted sound to return of the echo. With reference to the speed of sound in air, the exact distance of the liquid surface from the sensor can be calculated with high accuracy (±0.25% of maximum range).
Since the speed of sound is affected by air temperature, Greyline ultrasonic level sensors include a built-in temperature sensor. Level/distance measurements are automatically temperature compensated throughout the operating temperature range of the sensor.
The sensor should be positioned so that it has a clear “view” of the liquid surface and away from ladders, pipes or other obstructions. Greyline recommends 1 ft. from the sidewall for every 10 ft. depth (300 mm for every 3 m depth). False echoes from agitators (sweeping under the sensor), turbulence and waves can be filtered and disregarded by the instrument.
Greyline models range from simple 4-20mA level indicating transmitters, to sophisticated monitoring, controlling and logging models.
Use this versatile instrument to continuously measure, display, transmit and control liquid level in storage tanks and pumping stations. Mount the non-contacting ultrasonic sensor above the liquid being measured and install the watertight electronics enclosure nearby. Features of SLT 5.0 include user-friendly keypad calibration system, backlit LCD display, an isolated 4-20mA output and 2 programmable control relays.
Ideal for sewage pump stations, lift stations, wet wells and tank level control with a non-contacting ultrasonic sensor mounted above the liquid. The new Greyline PSL Level Controller has 6 independently programmable control relays for pump or valve control, level alarms, dialers, temperature alarm and echo-loss alarm.
This new Greyline Transmitter displays, controls and transmits level. Mount the non-contacting ultrasonic sensor at the top of your tank and the compact, watertight electronics/display enclosure at a convenient location nearby. Operators can calibrate the LIT25 with its 2-button Keypad, without climbing the tank. Use the built-in relay for level control or alarm, the large 4-digit display for local indication, and the isolated 4-20mA output to to transmit level to a PLC.