this is from the instruction sheet sounds like a TAN tester.
Understanding Contamination effects
The Oilyzer primarily reacts to the normal
increase in the acidity of oil, as it degrades
over time due to temperature, pressure,
and moisture. As the oil acidies, it will
begin to attack and pit metal engine parts.
A red LED reading typically indicates the
level of acids in the oil has reached a
maximum acceptable level, and the oil
should be changed. However, other
contaminants, such as dirt, soot, water,
anti-freeze and metal particles will also
influence the reading. Frequently testing
your oil (monthly) with the Oilyzer can
give you an advance warning of engine
problems, before they result in an expensive
engine failure. A sudden or unexpectedly
rapid drop in oil quality, or rapid ashing of
the red LED may indicate the presence of
one or more of the following contaminants:
• Water and anti-freeze may indicate
a bad seal or gasket.
• Metal particles may indicate rapid
wear of bearings, pistons, rings, etc.
• Excessive carbon or soot may indicate
poor compression or excessive blow-by.
• Fuel in the oil can give an articially
positive oil quality reading. If oil quality
does not drop as expected over time,
check for fuel leaks.
