PIOX® R is FLEXIM's Process Refractometer

In laboratories, Refractometers are quite common measuring instruments used to determine the purity, concentration and density of liquids as these properties are in distinct relation to their refractive index.
 
Within the last years, Refractometry has increasingly moved out of the laboratory and onto the production floor in order to take advantage of its benefits.
Unlike conventional critical angle inline Refractometers, the PIOX® R Refractometer utilizes the transmitted light principle. Based on the measured refractive index, the PIOX R transmitter calculates, by taking into account the media's temperature, the quantities relevant for a sophisticated process control (concentration, solids content, density, yield rate, etc.).
As the refraction measurement occurs directly in the probe volume flow and not indirectly at the boundary layer, PIOX R offers many advantages:
 

Drift free through differential measurement

With PIOX R, there is not only one light beam whose refraction is being measured, but two:

The monochromatic measuring beam is refracted by a biprism in two different directions. The difference between the two resulting peaks is measured. The patented measuring method ensures stable, drift-free measuring results, even in case of temperature and pressure fluctuations in harsh process environments. Moreover, in comparison to a critical angle Refractometer, PIOX R samples the entire medium cross section making the measurement results even more accurate.

 

Reliable even in case of fouling

If deposits form on the prism, an automatic adjustment of the LED's intensity occurs making PIOX R independent of fouling effects. Additional cleaning devices are therefore normally not necessary. When measuring media with a strong tendency to form deposits, the simultaneous evaluation of the signal amplitude makes it possible to trigger the required cleaning procedures. Maintenance efforts are thus kept to an absolute minimum.

 

Have a sharp glance at your process!

The PIOX R can be applied in a big variety of applications as it is not sensitive to pressure and temperature fluctuations or even the liquids viscosity. Versatile product types, materials and connection possibilities ensure the optimal integration into the process. Sapphire optics with high chemical resistance and mechanical hardness care for the special challenges in the chemical industry. Unique designs of the Refractometer for its usage in explosion hazard areas from ATEX Zone 2 to Zone 0 are available.

 

Transmitted light makes the Difference!

The measurement is highly accurate, fast, precise, reliable, environmentally friendly and, compared to the conventional laboratory analysis, very cost efficient. Further, the measurement is independent of the liquid’s color and turbidity and it is not affected by the presence of entrained gas and bubbles. Being adapted for the analysis of binary liquids (liquids consisting of two components), adding another measurement variable even allows the determination of three-components solutions.


In principle, all measurements which can be done in a laboratory setting can also be effectively and accurately accomplished in-situ using PIOX R.

 

Transmitted Light Refractometry Measurement Principle

Every substance is characterized by a specific relationship between its refractive index, the temperature and the concentration of its components. Once the refractive index and temperature of the medium are measured, the transmitter is capable of determining the concentration of the medium based on this relationship.

The PIOX® R Refractometer works with transmitted light. It determines the refractive index of a fluid on the basis of a measurement of the refraction angle of a light beam crossing a prism immersed in this fluid (Snellius' Law). The light emitted by the sensor's LED is parallelized and bundled before it crosses the fluid to be measured. At the surface of the measuring prism, the light beam is refracted and split in two.

On the CCD sensor behind the prism, two separate signals are detected. The distance between them is correlated with the refraction index through Snell's law. Together with the measured media temperature by the Pt1000 probe, the transmitter then calculates the temperature compensated refractive index nDT and other specific values such as m%, Brix or density.

By using materials selected for specific process needs, PIOX® refractometers offer the optimum solution to meet your analysis needs. The wetted probes comply with sanitary requirements for the food industry and are CIP-capable. Furthermore, models are available for especially corrosive chemicals.

PIOX® R suits a broad application range:

In many cases it serves within the Chemical and Processing Industries, in the Food & Beverage Industry, but also in metal processing, the mining industries or at airports during deicing operations.

Within these diverse processes, the process refractometer PIOX R cares for the concentration measurement in real time for a variety of different situations: from dosage up to the quality control of intermediate and end products.

To care for the proper hygienic environments, the sensing element (prism) is resistant to corrosive cleaning agents used during the CIP process (hot water, alkaline solutions, acids).

Chemical Industry

  • Concentration determination in distillation or rectification processes, or for solvent recovery
  • Acids (sulfuric acid, hydrochloric acid, acetic acid, etc.)
  • Dissolved metal salts (chlorides, phosphates, sulfates, etc.)
  • Organic solvents: - alcohols, glycols, -amines like MEA, DEA, EDA, -pyrrolidones, e.g. N-methyl-pyrrolidon (NMP)
  • Fungicides and fertilizers, e.g. urea ammonium nitrate (UAN)
  • Monitoring of the degree of polymerization during plastic and synthetic resin production processes
  • Concentration measurement of a blend of colloidal silica acid and water

Fiber Chemistry & Textiles

  • Control of the concentration of spinning solutions: -DMAC (dimethylacetamide), -DMF (dimethylformamide)
  • Concentration measurement of Caprolactam solutions (basic substance of the polyamide production)
  • Polycarbonates
  • Cellulose spinning solution

An application example within the Fiber Chemistry can found in acrylic fiber manufacturing, where a specific concentration of the solvent DMAC must be maintained during the entire processing cycle. PIOX® R monitors the concentration of the recycled solvent in order to keep the chemical properties of the fiber’s raw material stable for the production process.

Oil & Gas Industry

  • Control of the concentration of monoethylene glycol/water-blend during transport of natural gas

Facility / Airport management

  • Control of the concentration of the glycol/water-blend during de-icing processes of aircrafts

Food & Beverage Industry

  • Beet and cane sugar production
  • Continuous measurement of the sugar concentration for the regulation of a sugar heater
  • Continuous measurement of the sugar concentration in soft drinks and sweets
  • Continuous measurement of the original wort of the cold worth during the beer production
  • Metering of wine must (°Öchsle)
  • Beer analysis (alcohol measurement, wort, and original wort) in combination with a density meter
  • Continuous measurement of pastes and thick substances: liquid sugar, molasses, honey, jam, wine must, mash)
  • Whey products: Brix measurement, lactose, process control
  • Pectine

In sugar processing, refractometry is a precise and recognized method for determining the concentration of sugar solutions. During the production of mixed juices and soft drinks, refractometers are installed directly into the production stream to monitor the contents of mixing vessels and to maintain the desired sugar concentration.

Pharmaceutical Industry

  • Monitoring of the concentrations of ascorbic acid and cetogulon acid during the manufacturing of vitamin C
  • Nanogel
  • Various organica in process development and Pilot-Plants

Paper and Pulp Production

  • Starch concentration
  • Solids content in starch and casein based glues
  • Monitoring of solving processes in glue production

Research, Optics

  • Concentration measurement during crystal growth process
  • Process control of special etching solutions

Wastewater

  • Measurement of the max. solids content or mass % combined with monitoring turbidity of the fluid
     

Technical features:

  • Embedded standard-applications, e.g. determination of the sugar concentration in °Brix
  • Calculation of user defined output values: e.g. density, w%, Vol%, g/l, dry mass
  • Use of up to two sensors per Transmitter possible
  • Simple creation and management of user-defined data sets with the help of the RMKoeff Software
  • Measurement of ternary or higher substance mixtures on the basis of external values such as sonic velocity, density, conductivity, etc.)
  • Configurable with a multitude of application specific inputs and outputs
  • Explosion-proof models available (ATEX Zone 2); Sensor approved for ATEX Zone 1/0 can be connected

Customised Solutions -

Software RMKoeff for PIOX R

In some cases, the standard fluid parameters stored in the transmitter might not be adapted to your needs and your application. In this case, your own data sets must be defined and transfered to the PIOX transmitter. The software RMKoeff helps you with this task.

You will need an experimental determination of the relationship between the nDT and the wished output quantity. This can be done in your own laboratories or at the FLEXIM labs.

On the base of your data, RMKoeff will generate the characteristic curve of the fluid with polynomials of grade 1 to 3. You only have to enter the measured data in the appropriate table.

Your Advantages:

  • Simple creation and management of user-defined data sets
  • Automatic mathematical modeling 
  • Output quantity selectable by customer
  • Simple data transfer to the transmitter via RS232/USB
  • Easily understandable user interface
  • Suitable for all Windows™ versions

1.) Selection of the output quantity. Standard quantities such as w% and vol% are available in the default selection list. User-defined output quantities are also possible.

1.) Selection of the output quantity. Standard quantities such as w% and vol% - User-defined output quantities are also
possible.
2.) In order to define the relation between refractive index and output quantity, data pairs, – such as refractive index and w% – have to be entered in a table. These values are derived from technical literature or from measuring data collected by the user. 2.) In order to define the relation between refractive index and output quantity, data pairs, – such as refractive index and w% – have to be entered in a table. These values are derived from technical literature or from measuring data collected by the user.

3.) RMKoeff performs a polynomial curve fitting in order to generate a set of coefficients describing the entered data.

3.) RMKoeff performs a polynomial curve fitting in order to generate a set of coefficients describing the entered data.

4.) The PIOX® TR output can then be checked by entering test measuring values.

4.) The PIOX® TR output can then be checked by entering test measuring values.

 

5.) The calculated coefficients set is subsequently transferred to the transmitter via the serial interface.

 

Downloads

Technical Specification PIOX® R400
application/pdf, English, 314.97 KB
Brochure PIOX® R
application/pdf, English, 1.37 MB