There is a basic distinction between static fittings and retractable fittings. The static fittings are available as flow-through fittings, generally for by-pass or inline applications directly within the process flow, and as immersion fittings for measurements in basins, tanks, or channels.
Retractable fittings – better described from a functional point of view as “sensor lock-gates” – can be used to remove and service a sensor under process conditions. This is done in either manual or pneumatic mode. This can be linked with an automatic cleaning and/or calibration function. Because of the variety of production conditions, the requirements for a fitting are as diverse as they are for a sensor. Pressure and temperature, the choice of materials and above all the type and symmetry of the installation and the desired functionality, are determined by the fitting.
Ideally matched to the sensor lock-gates, the Unical 9000 and Uniclean 900 controllers provide for perfect fully automated interplay in a complete measuring station. Highly accurate measurements can then be taken, even under difficult process conditions such as high pressure, high temperatures, and high levels of impurities. When measuring in aggressive media or at high process temperatures, the sensor rests in the calibration chamber and is only briefly moved into the process for measurement. This method decisively increases the sensor life