3. Water & Environmental / Test Kits and Reagents / Water Analysers

Detection of fuel in AdBlue tanks with oil test paper


Adblue Oil test paper


AdBlue is the brand name of a 32.5% aqueous urea dilution. Truck engines with SCR catalytic technology use AdBlue to reduce the NOx-content in the exhaust gas stream. This reduction is necessary to reach the demanding limits for exhaust gases. The exact composition of AdBlue is defined in DIN 70070.
AdBlue is filled into a separate tank. Fuel in the AdBlue tank will permanently damage or destroy the SCR system, causing high cost of repairs. This can be tested for by using Machery Nagel test strips – Oil test paper


Move test paper back and forth 3-5 times.
Remove the test paper. A dark coloration indicates the presence of of fuel.
Different concentrations of fuel Left: pure AdBlue Right: pure fuel






Test procedure

The oil test paper is moved back and forth in the tank 3-5 times. A dark discoloration of the test paper indicates the presence of fuel.
Fuel does not mix with AdBlue. It forms small droplets or a thin layer on the surface of AdBlue. To give a positive reaction the test paper must come in contact with fuel in the tank.
Detection limit
50 mg/l fuel in AdBlue give a weak positive reaction. 100 mg/l fuel in AdBlue result in a clearly visible color reaction.

Product data and ordering information: Oil test paper

TypeQualitative test paper
PresentationPack of 100 strips 20×70 mm
Color reactionpale blue to dark blue
Limit of sensitivityPetroleum ether: 250 mg/l
Gasoline: 10 mg/l
Fuel oil: 5 mg/l
Lubricating oil: 1 mg/l

The full range of Macherey Nagel test strips are available from Camlab in the uk