Piston meters preferred over gear meters for AdBlue measurement

High accuracy meter for AdBlue

Piston meters are far superior to gear meters when measuring the flow rate of low viscosity fluids. The clearance between a rotating gear and the meter body is usually 5 times larger than the clearance around the pistons used in a Max meter. This larger internal leakage is the main reason that gear meters are calibrated using a 20 or 30 cps fluid. The operating range of a gear meter might be specified as 100:1 on a 20 cps fluid, but it will only maintain its accuracy over a 4:1 range when measuring 1.4 cps viscosity AdBlue. Applying a gear meter outside of its range of ability is not necessary. The emission testing industry has found a better alternative in the piston style meter. Compare the Model P213's calibration done on 3 cps fluid against any gear meter, including ours, and you'll see why gear meters are no longer specified for high accuracy measurements of fuels and diesel exhaust fluid.