New Pressure and Level Sensors at WWEM 2010

On stand 29 at this year’s WWEM (Water, Wastewater & Environmental Monitoring) exhibition (10-11 November 2010) at the Telford International Centre in Shropshire, sensor and instrumentation specialist Impress Sensors & Systems Ltd will be showcasing a range of new products, including submersible hydrostatic level transmitters and a multi-channel process controller.

The main focus of stand 29 will be Impress’ comprehensive range of submersible hydrostatic level transmitters. The SDI-12L for example, offers an SDI-12 digital output with an inbuilt high accuracy temperature sensor, which can be used in depths of up to 200 metres. This unit uses either a stainless steel silicon-based pressure sensor or a ceramic pressure sensor in marine-bronze. Both versions use piezoresistive technology, ensuring long-term stability and repeatability of measurements.

The SDI-12L is suitable for monitoring river and reservoir levels; tanks and vessels in process plants; seawater and estuary levels; borehole water levels; Tsunami and tidal monitoring systems; wave height measurement; environmental monitoring; and V-notch weir flow measurement.

The stainless steel version offers a higher resolution of pressure measurement to around 12-13 Bit and has a much lower signal-to-noise ratio, providing a very smooth and accurate method of level measurement.

The ceramic pressure sensor version is better suited to marine use, where standard devices may suffer from corrosion. These units are ideal for seawater, estuary and saline applications. Due to its SDI-12 compatibility, the transmitter can be corrected according to the specific density of the media being measured and local gravity can be set within the device, adding further to the accuracy of the unit.

The SDI-12L is just part of Impress’ comprehensive family of submersible hydrostatic level transmitters, which also includes ATEX-approved and SIL-rated level transmitters for hazardous areas; submersibles for aggressive media in PVDF, PVC and PEEK materials and for chemical dosing, SIP and CIP process. Other submersible transmitters are available with flush diaphragms for viscous or pasty media. Extremely high over-pressure units are also available, which protect transmitters in tank or pipe blockage situations.

Multi-channel controller
As well as submersible transmitters, Impress’ stand will also feature a full working demonstration of the company’s new compact, multi-channel, touch-screen controller, the CMC-99. This unit is ideal for the simultaneous measurement and control of a variety of water and wastewater applications, including intermediate pumping station measurement and control.

The CMC-99 controller provides an incredible variety of input and output combinations to suit individual customer requirements. The three card slots on the reverse of the controller each comprise 16 I/O pin options, which enable the user to choose any combination of inputs and outputs to suit the application. For example, up to 48 analogue current or voltage inputs could be used; up to 16 relay/SSR outputs; 24 thermocouple inputs; or 12 RTD inputs; or a combination of these. The unit also incorporates a 24V DC digital input, enabling relays and triggers to be set up.