SLM300C/800C/990C 4-20MA Ultrasonic Level Meter


The SLM300C/800C/990C series is a range of high quality ultrasonic level meters in explosion proof housings that provide non-contact level measurement of liquids and solids. Easy calibration and maintenance free “fit and forget” performance mean that you can install the SLM300C/800C/990C rapidly with confidence.

The SLM300C/800C/990C operates on the principle of timing the echo received from a measured pulse of sound transmitted in air and uses “state of the art” echo extraction technology.


  • Simple calibration
  • Easy installation
  • Aluminium diecast body
  • Explosion-proof construction
  • 4-20mA output
  • Display can be user configured to show level, space or distance   from sensor

Technical Specifications

Dimensions Overall:
300C, 120(D) x 251(H) mm
800C/900C, 120(D) x 260(H) mm
Accuracy 300C 0.25% of target range or 2mm
800C,990C 0.30% of target range or 3mm
Mounting 2 ½” NPT Resolution 0.03% of full scale or 1mm
Weight Nominal 3.2kg Beam Angle 10 at -3dB
Case Material Diecast Aluminium Damping Rate Adj. 0.1m/min to 10m/min
Sensor Material Aluminium Temperature Comp. Fully compensated
Measuring Range 300C 0.25 to 3m
800C 0.30 to 8m
990C 0.30 to 10m
IP Rating IP67 Analogue Output 4-20mA into 600Ω
Temperature -20C to +70C Sensor Com Port RS232 / RS485 (Option)
Pressure 2 bar max. Display 4 digit LCD display
Certification CE
Explosion Proof Ex dm II B T6
Supply Voltage 20 to 30VDC
Current Consumption Less than 21mA