IMP+ INSTRUCTION MANUAL 
 
6 
About the IMP+ 
 
Functional Description 
The IMP+ level monitoring system is a highly developed ultrasonic level 
measurement system which provides non-contacting level measurement for 
a wide variety of applications in both liquids and solids. Its unique design 
allows for both 3 wire and 2 wire (loop powered) configuration all within the 
same unit.   
Easy calibration and maintenance free “fit and forget” performance mean 
that you can install the IMP+ Level Monitoring System rapidly and with 
confidence. Two relays which can be configured for either alarm or control 
functions, with fully programmable setpoints are provided when connected 
as a 3-wire device, together with fault condition being indicated by the mA 
output on both the 2 and 3 wire mode. 
The IMP+ operates on the principle of timing the echo received from a 
measured pulse of sound transmitted in air and utilises “state of the art” 
echo extraction technology.   The IMP+ comes in three models: IMP 3 with a 
range from 0.20m (0.66 feet) to 3.00m (9.84 feet), IMP 6 with a range of 0.3m 
(0.98 feet) to 6.00m (19.69 feet) and IMP 10 with a range of 0.3m (0.98 feet) 
to 10.00m (32.81 feet). 
The IMP+ can show level, space, distance, on the display. The relays can be 
programmed to give an ‘ON’ and ‘OFF’ point for external control. There is a 
4-20 mA output (non-isolated in 3 wire mode) that can be connected to a 
remote chart recorder or PLC, to monitor level, space or distance, dependant 
on the measurement mode selected, and provides a ‘fault condition’ alarm 
of either 3.5mA or 22mA. 
The IMP+ lid has an integral LCD display and 4 buttons which are used for 
programming purposes when in Program Mode and as hot keys providing 
additional information whilst in Run Mode.