The Bellingham + Stanley OPTi range of application-specific instruments and custom models cater for a wide range of industrial uses, particularly where expression of the reading needs to be displayed in units relevant to the solution under test or must comply with local regulations. Additionally, for "non sugar" solutions that cannot use commonly adopted "Brix" sugar temperature compensation, these OPTi refractometers may be programmed with correction factors specific to the solution under test. This and the direct digital readout results in a higher level of accuracy when compared to other makes of digital and all optical refractometers for "non sugar" analyses. Also, most application-specific and custom OPTi refractometers are 'Duo' models, providing two measurements from a single hand held device. Whether it is grapes or apples being tested in the field to ascertain the optimum ripeness for harvest, dilution testing of automotive or industrial heat pump systems, analysis of salt solutions in aquaculture or aquaria, body-fluid testing by veterinarians, or sportspersons looking to enhance their performance by ensuring optimal hydration - OPTi provides a solution for all solution analyses!