Refractometers

Group 1 - Small instruments.
These are small handheld or palm size instruments costing from $200 to $2000. Typically these Refractometers cover portions of the Brix range low middle or high. or they have other application specific concentration scales - wine, protein, urine specific gravity, antifreeze, battery acid and others. These small instrument can be subdivided into two types. 
Hand held manual Refractometers $150 - $500
You hold these up to the light and look through the eyepiece. These are inexpensive but more cumbersome to use than an electronic type. They don't need batteries or power so they can be used anywhere anytime - at least in daylight. 
Small Electronic Refractometers $750 - $2000.00
These cover the same range as the manual types - they are the electronic 'replacements' for the manual type. Because they are digital and produce a readout they are less prone to operator error. Typically they include automatic temperature compensation.
Use group 1 instruments for non critical applications, quick checks, back up and portability. Ideal as personal instruments for QC personnel traveling to different locations.

Group 2 Laboratory Refractometers $5000 - $7000
These Refractometers are much more robust than the small electronic units. They have a better underlying accuracy (expressed as the index resolution - typically at least 0.0001) which translates into a better Brix accuracy 0.01 - 0.05. Many regulations specify Brix to the first decimal place so using a refractometer with a basic accuracy better than 0.1 is important. Group 2 Refractometers are simply more accurate and better built than the small units. They have sapphire prisms and sealed optics. A computer interface is usually a standard feature for printing and data download. Productivity features include flow through modules and temperature stabilization accessories
Use group 2 instruments for quality control, record keeping and heavy workloads. If you make 100s of tests per day you should choose from this group

Group 3 High Performance Laboratory Refractometers $7000 - $11000
High performance Refractometers have the same robust construction as the laboratory types in group 2.  The accuracy is at least 0.00002 with a resolution to the 5th decimal place 0.00001. Instruments in the group may include the full index range out to 1.70000 and electronic temperature control of the sample area. Advanced features include computer interfacing, custom programming of concentration scales and interfacing with polarimeters.
Recommended for research and demanding application which require high accuracy and temperature dependent data.

Group 4 Inline process Refractometers $8000 - $11000
Process Refractometers are designed for inserting into pipelines or vessels to monitor a process variable (typically dissolved solids) which is refractive index dependent. There are two types. The first type is self contained with a flange mounted refractometer head and a remotely mounted electronic console which communicates with the sensor displays the data and can produce auxiliary outputs in analog or digital format. The second type is an index transmitter. In these Refractometers the optics and electronics are all contained in a compact flange mounted unit. The refractometer produces a digital and analog output ready for transmission to a PLC or other controller.

• BRIX
• OTHER SCALES
• Refractive index nD
• Clinical Refractometers
• Wine Refractometers
• Salinity
• Honey
• Industrial Fluids
• More special scales

All types - for Brix, Urine, specific gravity, protein in serum,
salinity, antifreeze, alchohol, wine, industrial fluids oils etc. Inexpensive.