Process refractometer PIOX R400


Refractometry – in other words, the measurement of light refraction – is a well-established method of choice for determining the concentration, density and purity of many liquids. By measuring the refractive index directly within the process, PIOX® R allows for a highly accurate measurement, long term reliability and continuous quality management either in hygienic and ultraclean sanitary or harsh industrial environments with high process pressures, temperatures and corrosive media. Unlike other available measurement technologies, FLEXIM’s PIOX® R employs its patented transmitted light principle and thus never bears the risk of measurement drift and  false readings from deposit build up at the prism. The unrivalled design and the integrated diagnostic tools moreover allow for very cost effective and predictive maintenance intervals.

FFKM gaskets, scratch resistant sapphire optics, as well as the complete separation of the sensor head from the electronics compartment. For measuring toxic and corrosive organic as well as inorganic media, PIOX® R is offered as a fully stainless steel design variant with all wetted materials made out of grade 316 Ti /1.4571 steel. When measuring in highly corrosive media, such as hydrochloric, strong sulfuric or hydrofluoric acid, PIOX® R is available as a special carbon fiber reinforced PTFE design variant offering an unrivalled corrosion resistance, long term stability and reliability in such harsh environments. Being ATEX Zone 0/1, 1 and 2 certified and available with long and short sensor heads that can be integrated into the process via DIN / ANSI flange or the proprietary FLEXIM flow cell, PIOX® R is the ideal process analytical technology for a wide array of liquid media within the chemical industry.

Technical data

Process Refractometer; Measurement according to the patented Transmitted Light Principle

Measuring quantities
(temperature compensated) Refractive index, media temperature, ° Brix (Plato, Oechsle), w%, additional quantities programmable

Measurement range
nD: 1.3 …1.7, °Brix: 0 …100

Measurement accuracy
nD: 0.0002; (corresponds to: 0.1 °Brix, 0.1 w%)

Operating temp. (media)
– 20 °C … (+ 130 °C) + 150 °C

Fluid pressure
PN 10, PN 16, on request PN 40 (depending on process connection)

Degree of protection / Explosion protection:
Sensor: IP67, ATEX (IECEx) Zone 0/1, 1, 2
PIOX® R704: IP65, ATEX (IECEx) Zone 2 optional
PIOX® R705: IP66, stainless steel enclosure,
ATEX (IECEx) Zone 2 and FM Class I, Div. 2 optional
PIOX® R709: 19 inch rack version, IP20

Additional information




Chemical and petrochemical industry, Food industry, Pharmaceutical and cosmetics industry, Printing houses

Measured parameters

Concentration, Density