Low Level Alarm & Monitor - cabled

Product Description

This wireless, low liquid level monitoring system is available as a low-cost option and can be fitted to Above or Below Ground tanks, indeed, fitted to almost any plastic or metal tank between 0.5m and 3m in height. It is most often used to safely monitor low liquid levels in tanks positioned at height or positioned in inaccessible places e.g. underground.

This unit is effectively the same as our standard Apollo low level alarm except that the sensor and transmitter are separated into two distinct parts (see gallery and/or product sheet, below). The sensor is mounted in a robust 4cm diameter x 3cms plastic housing, which is fixed to the tank and which in turn connects by a 10m cable to the battery-powered transmitter.

The sensor is mounted on the tank (i.e. below ground, at height or in a hard to reach place) and emits ultrasonic waves to measure liquid height in the tank. This liquid height is transferred via the 10m cable to the transmitter, which is mounted in a safe, accessible place and which uses wireless technology to send tank levels to the plug in receiver unit for the user to view at their convenience.

The receiver plug unit is generally plugged in to a 230v power socket within 200m of the transmitter and gives audible and visual warnings of tank levels from about 80% full. The Apollo XT Low level unit makes the monitoring of inaccessible tanks simpler and safer, achieving Health & Safety requirements whilst also avoiding unnecessary call outs for refills.


Tank Depth Measurement
Minimum depth: 0.5m / Maximum depth: 3m
Alarm Details
  • Transmitter = 125 mm tall x 45 mm wide.
  • Sensor = 30 mm tall x 45 mm wide.
  • Sensor is vertically-mounted on top of tank. Ultrasonic beam points down at liquid and bounces back into the sensor, which sends the data by cable to the transmitter which then communicates wirelessly with the plug in receiver.
  • Clearance of 130 mm required abovce receiver.
  • Receiver = same size and appearance as a standard 3-pin plug (55 mm tall x 50 mm wide). Antenna projects 140 mm above unit.
  • Both transmitter and receiver have LCD displays showing level.
Alarm Volume
67.5 dB
Alarm Frequency
5 beeps from plug-in receiver of 1 second duration every hour (must be powered on)
Alarm Levels
First warning given at 20% from empty
Max Communication Distance
200m in normal 'line of sight' conditions
Power Supply (Receiver)
150-250V, 50-60Hz. EN 60335
Power Supply (Transmitter)
3 Volt Lithium Cell (3V-CR2450)
Transmitter Battery Life
7-10 years (estimated life)
Wireless Communications
433 mHz. FM Transmission. EN 300-220
Max and Min Operation Temp (Transmitter)
Operating temperature range: -10 to +60 Degrees Celsius



  • A tank-mounted sensor is positioned on the tank is connected to the transmitter via a 10m long cable. Once the transmitter and receiver are paired, the transmitter generates a unique RF (radio-frequency) code tying it to the monitor / receiver (which stores the code internally and indefinitely). Upon powering up, the monitor will associate with the appropriate RF code. This means that equipment can be prepared before shipment to site, particularly relevant for the hire industry.
  • A visual scale is displayed on the receiver unit and warning tones sound (from the receiver unit) when the tank is close to empty: typically from 20% to empty.
    This will be the time to make the call to your service provider.
  • In the event of power failure, when the power is restored the two units will find each other but it may take 1-2 hours for correct levels to be recorded. Therefore, it is recommended that the receiver is left powered on where possible.
  • Should equipment become mixed up (e.g. if hire equipment is moved from site to site many times during its lifetime) then it is suggested that transmitter and monitor are paired again to make doubly sure that the local equipment is matched.
  • You can avoid the situation where the first time you're aware your tank is empty is when the toilets no longer flush, for example! Those emergency call-outs tend to be most expensive.

WARNING: As with all wireless devices, actual performance may be affected by thick walls / heavy machinery / Faraday cage scenarios between transmitter and receiver.

Features and Benefits

  • Remotely monitor your waste levels and ensure you never overflow again with this reliable, accurate and secure gauge
  • The tank mounted sensor can be easily fitted to a tank above or below ground due to the 10m long cable to the transmitter: the receiver can be connected to any standard domestic power socket in your home or site office (within 200 m range - in line of sight, optimum conditions)
  • Available with a 3 pin UK / Ireland plug
  • The monitor removes the need for a physical, visual check and particularly helps where your tank is difficult to access
  • Achieve compliance with Health & Safety requirements by allowing waste to be monitored safely and accurately without the risks involved with working at height or with underground tanks


Apollo XT Sensor, Transmitter, ReceiverReceiverReceiverReceiver
Call for FREE in the UK:

0800 334 5742

International: +44 (0) 1922 716 725
Email our team: