RFM990 Flow Model

The Refractometer
The RFM990 Flow refractometer is a wide range Peltier temperature controlled instrument that has been specifically designed for flow applications. The instrument incorporates a special stand that elevates the instrument to an optimum angle as well as a bubble loop on specific cells, ensuring that sample is presented to the prism without entrapped air and therefore ensuring best performance in the most difficult flow configurations. 

Supplied as an instrument module only, the customer can choose from a number of standard cells or for special applications, a custom design chamber may be offered at extra cost depending on viability. 

Available as a five decimal place RI instrument only, customers requiring a lower level of accuracy have the option to switch the resolution. 

Measurement Specifications

RFM990 Scales   Refractive Index   Sugar (°Brix)   User-defined 1.30 – 1.70 0-100 yes Resolution   RI   Sugar (°Brix) 0.00001 or 0.0001    0.01 or 0.1   (user selectable by software function) Accuracy   RI   Sugar (°Brix) ±0.00002 or ±0.0001    ±0.02 or ±0.1   (user selectable by software function) Temperature Compensation   Sucrose (°Brix)   AG Fluids   User-defined 5 – 80 °C Simple coefficient (units/ °C) or polynomial function Reading Time (s) Minimum 4 seconds Temperature Stability Checks None/delay time/repeatability/Smart (independently selectable by product profile) Measuring Temperature Range 0 °C or 10 °C  below ambient whichever is the greater to 80 °C Temperature Sensor Accuracy ± 0.03 °C Sample Temperature Stability ± 0.05 °C

Chamber material 316 Stainless Steel Prism material Synthetic Sapphire Prism seal Kalrez®

The Flowcells
When installing an RFM990 in to a flow system, a flowcell must be selected and depending on the application, a choice can be made from the following:

Micro flowcell:
Micro flowcells are typically used in conjunction with an autosampler. Typical applications include use with density meters and/or polarimeters in breweries for calculating alcohol content and flavours & fragrance applications. Micro flowcells are also used in beverage applications, especially in ‘audit laboratories.’

Macro flowcell:
Macro flowcells are used where sample viscosity limits the use of micro-flowcells or for connection to a pilot or small-batch process line, where a normal process refractometer may not be suitable.

Macro funnel flowcell:
Where larger volumes of sample are available, funnel flowcells are often used. These negate the need to clean the instrument prism between sample measurements, providing a rapid sample turnaround, such as in Tare Houses of grape growers co-operatives and sugar mill receiving stations. There are two funnel sizes available.

Specifications

Micro Macro Funnel* Micro-UNF Code 22-91 22-92 22-93 22-95 Cell volume (including nozzle) ml 0.6 1.2 1.2 0.6 Flushing volume ml - - 50-100 - Sample inlet tubing bore mm 2 4 - 2 Sample inlet/waste nozzle outside diameter mm 3 6 6 3 Sample waste tubing bore mm 2 4 6 2 Sample pressure bar 2 2 - 2 Stand dimensions:   Width   Depth   Height   Weight mm mm mm kg 230 330 430 2 230 330 430 2 230 330 230 330 430 2 Connections Pushfit ¼” UNF Chamber material PEEK Nozzle material 316 Stainless Steel Sealing ring Chemraz®

*Standard size funnel (85mm) code 22-93.
*A large diameter (150mm) funnel flow cell is available code 22-94.

Materials in contact with the sample

RFM990 Prism Gasket Chamber        Synthetic Sapphire Kalrez® 316 Stainless Steel Flowcell Chamber Sealing Ring Connections PEEK Chemraz® 316 stainless Steel

Materials Traceability Certificates are available on request as an optional extra and must be included at point of order. Delivery time may be extended when requesting such certification.

Special Connectors:
For hazardous samples, secure connections such a Swagelok® may be offered as a custom solution.  Contact the Sales Team for details.

Further information on autosamplers, barcode readers and flowcells may be obtained by referring to product specific literature and/or Technical Bulletins where applicable. For details, or to discuss a particular application, please contact Bellingham + Stanley or an approved distributor.