Draper Expert Adblue® Refractometer Kit

The Draper Expert ARFR AdBlue® Refractometer Kit is a precision optical measuring instrument designed for testing urea concentration in AdBlue® diesel exhaust fluid and measuring antifreeze strength in vehicle cooling systems. Covering a urea measurement range of 0 to 40% and an antifreeze range of 0 to -50°C, and featuring an Automatic Temperature Corrected (ATC) prism for accurate readings regardless of ambient temperature, the ARFR provides the professional workshop, fleet operator or vehicle technician with a fast, reliable and cost-effective method of verifying AdBlue® quality and coolant freeze protection without the need for laboratory analysis or expensive specialist equipment.

Compatible with both ethylene glycol and propylene glycol antifreeze formulations, and supplied with a calibration screwdriver, calibration fluid, pipette, cleaning cloth and storage case, the ARFR is a complete, self-contained kit ready for immediate professional use.

What's in the Kit?

The ARFR contains everything required for accurate AdBlue® and antifreeze measurement:

• Precision Refractometer — The core instrument, featuring a focusable eyepiece for sharp, clear scale reading and an ATC prism for automatic temperature compensation. The dual-scale internal optics display both the urea concentration percentage and antifreeze freeze point temperature simultaneously, allowing the correct scale to be read directly for each test type.
• Calibration Screwdriver — Used to adjust the refractometer's zero calibration point, ensuring measurement accuracy is maintained over the instrument's working life and after any period of storage or transport.
• Calibration Fluid — Reference fluid for accurate zero calibration of the refractometer, ensuring the instrument is correctly set before measurement commences.
• Pipette — For accurate, controlled transfer of small fluid samples — AdBlue® or antifreeze — onto the refractometer prism for testing, without contamination or waste.
• Cleaning Cloth — For cleaning the refractometer prism between samples and after use, preventing cross-contamination between test fluids and maintaining the optical clarity of the prism surface for accurate readings.
• Storage Case — Protects the precision optical instrument between uses, preventing damage to the prism, eyepiece and internal optics during storage and transport.

Key Features

• Precision refractometer for measuring urea concentration in AdBlue® diesel exhaust fluid (0–40%) and antifreeze freeze point (0 to -50°C)
• Automatic Temperature Corrected (ATC) prism ensures accurate readings regardless of ambient temperature — no manual temperature correction required
• Focusable eyepiece for sharp, clear scale reading across all user vision types
• Compatible with both ethylene glycol and propylene glycol antifreeze formulations
• Complete calibration kit included — calibration screwdriver and calibration fluid
• Pipette and cleaning cloth for clean, accurate sample handling and prism care
• Packed in storage case for protected instrument storage and transport
• Manufactured to Draper Expert's professional quality standards

Understanding AdBlue® and Why Concentration Matters

AdBlue® is a high-purity aqueous urea solution — a precisely formulated mixture of 32.5% urea and 67.5% deionised water — used in Selective Catalytic Reduction (SCR) exhaust aftertreatment systems on diesel vehicles to reduce harmful NOx emissions. It is a legal requirement in modern diesel vehicles fitted with SCR systems, and its quality is tightly regulated under the ISO 22241 standard.

The urea concentration of AdBlue® is critical to correct SCR system function. If the concentration is too low — whether due to dilution with water, deterioration over time or the use of substandard fluid — the SCR catalyst cannot reduce NOx effectively, resulting in failed emissions compliance and potential SCR system fault codes. If the concentration is too high, the fluid can crystallise in the SCR system's injector and lines, causing blockages and expensive component damage.

The ARFR's 0–40% urea measurement range allows the correct 32.5% concentration to be confirmed quickly and accurately — identifying whether a suspect AdBlue® supply or an existing tank fill is within specification before it enters the vehicle's SCR system. This is particularly valuable for fleet operators, agricultural users, workshops topping up customer vehicles, and anyone refilling from bulk storage where contamination, dilution or deterioration may have occurred.

Understanding Antifreeze Measurement

The ARFR also measures the freeze point of ethylene glycol and propylene glycol antifreeze solutions across the range of 0 to -50°C — allowing the coolant's freeze protection level to be confirmed quickly during service or following coolant top-up. Correct antifreeze concentration is essential for year-round engine protection: too weak and the coolant risks freezing and expanding in the engine block in cold conditions; too dilute in the additive package and corrosion inhibitor protection is compromised across the cooling system's aluminium, steel and rubber components.

The ATC prism compensates automatically for the temperature of the sample being tested, removing the need for manual temperature correction calculations and ensuring the freeze point reading is accurate regardless of whether the sample is taken from a warm engine or a cold environment.

Why Choose the Draper Expert ARFR?

AdBlue® quality testing has become an increasingly important diagnostic capability as the proportion of SCR-equipped diesel vehicles on UK roads continues to grow — spanning passenger cars, light commercial vehicles, HGVs and agricultural machinery. In a workshop context, the ability to quickly verify AdBlue® concentration before topping up a customer's vehicle, or to test a suspect batch of fluid that may be causing SCR system warnings, can save significant diagnostic time and prevent expensive SCR catalyst or injector damage from substandard fluid.

The ARFR's ATC prism is the feature that distinguishes a professional-grade refractometer from a basic instrument. Without automatic temperature compensation, a reading taken in a cold workshop or from a warm engine sample will be inaccurate unless a manual correction is applied — introducing the potential for error precisely where accuracy matters most. The ATC prism eliminates this variable entirely, delivering a temperature-corrected reading automatically from the moment the sample is applied to the prism.

The inclusion of a complete calibration kit — screwdriver, calibration fluid, pipette and cleaning cloth — reflects the Draper Expert range's commitment to providing everything needed for professional use from the moment of purchase, rather than requiring additional accessory purchases to put the instrument into reliable service.

The Draper Expert range is trusted throughout the UK professional workshop trade for precision engineering, build quality and genuine value.

Ideal Applications

The ARFR is suitable for AdBlue® and antifreeze testing across a wide range of professional and operational contexts, including:

• Workshop AdBlue® top-up verification — confirming the concentration of AdBlue® before filling customer vehicles, particularly when using bulk storage or non-OEM sourced fluid
• Fleet maintenance — rapid AdBlue® quality checks across a fleet of diesel vehicles during scheduled maintenance visits
• Agricultural and plant machinery — testing AdBlue® quality for tractors, combine harvesters and construction plant fitted with SCR systems
• SCR fault diagnosis — testing existing AdBlue® tank contents as part of SCR system fault investigation where fluid quality may be a contributing factor
• Antifreeze concentration checking — verifying coolant freeze protection during seasonal servicing, post-flush refill verification and cooling system top-up quality control
• Pre-purchase vehicle inspection — confirming both AdBlue® and coolant quality as part of a comprehensive pre-sale or pre-purchase vehicle health check

Frequently Asked Questions

Q: What is the correct AdBlue® urea concentration and how does the ARFR help confirm it? AdBlue® should contain exactly 32.5% urea by weight, as specified under ISO 22241. The ARFR measures urea concentration across the 0–40% range, allowing the 32.5% specification to be confirmed directly from a small sample — identifying whether the fluid is within tolerance, too dilute or too concentrated before it is used in a vehicle's SCR system.

Q: What does Automatic Temperature Correction (ATC) do? The ATC prism automatically compensates for the temperature of the fluid sample being tested, ensuring the reading displayed is accurate regardless of sample or ambient temperature. Without ATC, refractometer readings vary with sample temperature and manual correction calculations are required — introducing the potential for error. The ARFR's ATC prism eliminates this completely, providing a reliable, temperature-corrected reading every time.

Q: Does the ARFR work with both ethylene glycol and propylene glycol antifreeze? Yes. The ARFR is designed for use with standard ethylene glycol and propylene glycol antifreeze formulations, covering the two most widely used coolant types across passenger cars, light commercial vehicles and other applications.

Q: What antifreeze freeze point range does the ARFR measure? The ARFR measures antifreeze freeze point from 0°C to -50°C, covering the full range of antifreeze concentrations from neat water through to the maximum recommended antifreeze mixture for even the most severe operating conditions.

Q: How is the refractometer calibrated? The ARFR is calibrated using the included calibration fluid and calibration screwdriver. Apply a small amount of calibration fluid to the prism, look through the eyepiece and adjust the calibration screw until the boundary line aligns with the zero point on the scale. Regular calibration — particularly before important test results — ensures measurement accuracy is maintained throughout the instrument's working life.

Q: How much fluid is needed for a test? A refractometer requires only a very small sample — typically two to three drops — applied to the prism using the included pipette. This makes it practical for testing AdBlue® or antifreeze from vehicle systems without draining significant quantities of fluid.

Q: Is the ARFR supplied in a storage case? Yes. The ARFR and all accessories are supplied in a storage case that protects the precision optical instrument during storage and transport between uses.