Bag Mini Diluter
The Bag Mini-Diluter is an alternative to Constant Volume Sampling (CVS) Techniques and provides the improvements necessary to address the testing of Partial Zero Emission Vehicle (PZEV) and Super Ultra-Low Emission Vehicle (SULEV) emissions. The differences between Bag Mini Dilute and CVS sampling are as follows:
- Sample is diluted with zero air – eliminates problems with ambient bags having higher concentration than sample bags.
- Dilution ratio is smaller – typically 5 to 1, making bag concentrations higher.
Features of Bag Mini Diluter
The drawing shows the key components that make up a Bag Mini Diluter system. There are several critical factors for Bag Mini Diluter accuracy that must be understood. They are:
- Accurate determination of critical flow venturi (CFV) flow-rates (dilution ratio).
- Achieve sonic flow on the CFVs.
- Maintain equal pressure and temperature for the sample and dilution CFVs.
- Accurate measurement of tailpipe exhaust flow-rate.
- Maintain proportionality of Bag Mini Diluter bag fill flow-rate to tailpipe exhaust flow-rate (requires an accurate determination of gas transport delay time).