The SRV is a stable, robust sensor system that operates over a wide range of temperatures and pressures. The sensor is made of 316L stainless steel, which resists attack by a wide variety of highly corrosive fluids.
In order to get optimum performance from the system, some simple guidelines must be followed.
Cleaning the sensor
The SRV is based on a resonant sensing element that operates in the range of approximately 7-8 kHz. The sensor measures viscosity in a thin layer of fluid surrounding the resonant element.
In any measurement scenario in which the sensor could become coated with tenacious fluids and solids, it is recommended that the sensor be removed and mechanically cleaned at appropriate intervals.
Adherent films can be removed by using appropriate solvents, ultrasonic cleaning, and/or wiping with solvent-saturated cloth or paper. Under no circumstances should abrasives be used to clean the resonator, as these will change the geometry and destroy its calibration.
Cleaning the sensor with solvent-saturated cloth or paper
Please note that it is difficult to get accurate measurement with plain water stationary in the SRV measurement area. Even degassed water tends to have air dissolved in it, which eventually forms micro bubbles on the surface of the sensor, disturbing its geometry. This is not a problem at higher pressures, which tend to re-dissolve any gases present. Hydrocarbons, glycols, and other fluids with low surface tension are less prone to bubble formation.
The SRV will operate in static fluids as well as flow rates in excess of 100 l/min. Flow may be in either direction, subject to the above caution about the effects of bubbles.