Across the world, millions of trucks move the goods we all rely on. But with that movement comes a responsibility to protect the air we breathe. That’s where diesel exhaust fluid (DEF) plays a vital role. Known as AdBlue in Europe and Asia, BlueDEF in North America, and Arla 32 in Brazil, this simple, clear liquid helps reduce harmful emissions that once caused smog and acid rain.
It’s a small step, but it makes a big difference: cleaner skies, healthier cities, and fresher air. DEF production starts with fertilizer companies like Yara in Europe or Cherokee Nitrogen and CF Industries in the United States. From there, wholesalers package the fluid—often in bulk containers like IBC totes—and send it to retailers. Finally, it reaches fueling stations like Pilot and Flying J, where truckers can conveniently fill up at the pump.
But whether you’re a producer, wholesaler, or retailer, quality is what matters most. DEF must meet strict international standards such as ISO 22241. Compliance requires full laboratory testing setups—drying ovens, tall-form beakers, deionized water, reference curves, and repeated measurements at exactly 20°C.
A critical part of this testing process is the refractometer. Rudolph Research offers two refractometers designed specifically for ISO 22241 compliance: the J57 HSA B and the J157 HAA B.
Here’s how these instruments meet the standard:
Wavelength: ISO 22241 specifies 589.3 nm ±5. Both the J57 and J157 meet this requirement.
Measuring range: The standard requires coverage from 1.33000 to 1.39000. Rudolph instruments fall well within this range.
Temperature stability: Refractometers must hold 20°C within ±0.1. With solid-state Peltier control, Rudolph ensures precise temperature management.
Resolution: ISO requires readings to the fifth decimal place. Rudolph delivers exactly that.
Accuracy: The standard allows no more than ±0.00005 RIU after calibration. Rudolph refractometers exceed this, achieving ±0.00002 RIU accuracy.
Urea content calculation: The J57 HRA follows the ISO calculation but requires manual entry of the biuret value. The J157 HRA allows users to enter the biuret value directly, making it the better choice when this factor is critical.
Calibration verification: ISO requires monthly checks using deionized water and at least three certified reference materials. If values deviate beyond the fifth decimal place, recalibration is necessary. To simplify this, Rudolph provides a kit of three urea standards, accurate to the fifth decimal place and manufactured under ISO 17034.
Beyond these requirements, the instruments differ in features:
The J57 has a smaller footprint and connects to a strip printer.
he J157 offers network connectivity, supports more printer options, and provides additional modes for greater flexibility.
For labs with broader needs, Rudolph also offers the J357 and J457, which go beyond ISO 22241 testing by adding advanced measurement capabilities for other materials.
With Rudolph instruments, your lab can be confident of full ISO 22241 compliance, backed by accuracy, reliability, and robust features tailored to your workflow.
Contact Rudolph Research Analytical today for a consultation, a demo, or to request a quote—and discover why leading laboratories around the world trust Rudolph for DEF testing and refractometry.
