Process refractometer
A process refractometer is installed directly in a pipe or in a tank in order to continuously measure the concentration of a liquid substance mixture.
Sensors and control devices are designed as field devices . The direct installation of a refractometer in harsh process environments results in special requirements such as: B. Explosion protection , compatibility with high and low temperatures and high quality materials that are resistant to aggressive chemicals. Where direct installation is not possible or makes no sense, process refractometers are connected via a bypass.
The sensor measures the refractive index and the temperature of the sample medium. The control unit uses this to calculate the concentration of substance mixtures. The tasks of a process refractometer are mostly quality control and process optimization. Common areas of application are the processing of foodstuffs, the chemical industry and pharmaceuticals.
The control device provides analog outputs (e.g. 4-20mA current interface ), digital outputs (e.g. fieldbus ) and alarm outputs (e.g. relays ) for a connection to a process control system or a PLC .
The first process refractometer REMAT20 (REfraktoMeterAutomaT) was developed by VEB Carl Zeiss Jena and presented at the Leipzig spring fair in 1976. Current devices are designed as digital measuring devices with no moving parts.
Individual evidence
- ↑ Trade fair special supplement of the Jenaer Rundschau 1976.