This AdBlue refractometer is a hand-held optical instrument for rapidly checking the concentration of AUS 32 (AdBlue) urea solution in vehicle and plant SCR systems. Its primary use is to verify that AdBlue is within the correct concentration range specified by fuel emissions systems — typically 32.5% w/w urea — so that selective catalytic reduction (SCR) hardware operates correctly and to help avoid crystallisation or injector blockages.

The instrument features a precision BK7 optical prism and an anodised aluminium alloy body with a rubberised outer sleeve for impact resistance and secure handling. The sample well and internal fluid paths are stainless steel to resist corrosion from urea solutions. The refractometer provides a measurement range of 0–50% w/w urea concentration with a resolution of 0.1% and a stated accuracy of ±0.2% at 20°C. Automatic temperature compensation (ATC) is incorporated to reduce error from normal ambient temperature variation, and a small calibration screw allows adjustment using distilled water. As an inspection tool rather than a laboratory instrument it is intended to be used in accordance with ISO 22241 (AdBlue/AUS 32) guidance when confirming product quality on site.

Typical users include vehicle workshops, fleet maintenance depots, agricultural and construction plant service teams, commercial haulage operators and fuel/oil distributors who need a quick field check of AdBlue concentration. It is useful during refilling, tank transfers and routine servicing to ensure compliance with manufacturer requirements and to prevent SCR faults that can be expensive to diagnose and repair.

Key benefits include chemical resistance where it matters (stainless wetted parts and anodised housing), direct readout in % w/w for immediate decision-making, small sample volume requirements and straightforward field calibration. The unit is compatible with AdBlue/AUS 32 solutions and similar aqueous urea blends; it is not suitable for other fluids such as glycol antifreeze or concentrated acids without prior dilution and appropriate laboratory methods.

Duchy Fasteners stocks this Draper Tools Group D AdBlue refractometer (DR23193) as a single unit supplied with a protective case, calibration screwdriver and instructions. Replacement parts and additional workshop testing tools are available; please contact us for pack, bulk or accessory options.