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Old 07-18-2003, 06:43 PM   #2
Jon [in CT]
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Member#: 2992
Join Date: Nov 2000
Chapter/Region: NESIC
Location: Connecticut, USA
02 WRX Sedan


Their meter is probably a fine product, but they apparently couldn't resist over-hyping it.

One of its claimed features is:
Self-calibrating and self-compensating for pressure and temperature variations
However, in the user manual in Section 4.1, there is this warning:
On turbo charged vehicles:

Install the sensor downstream from the turbo before the catalytic converter. The high exhaust pressure before the turbo interferes with the lambda measurement and the high exhaust temperatures encountered there can damage the sensor.
High exhaust temps are unlikely to actually damage the sensor (the WRX's front A/F sensor, mounted upstream from the turbo, is proof of this). However, the sensor won't work if the EGT is higher than the sensor itself. And compensating for high exhaust pressure is possible (see, but the LM-1 sure isn't doing this.

Another claimed feature is:
Significantly more accurate than analog/conventional method
And in their press release, they go a little bit further:
Competing air-fuel-ratio meters vary widely in their precision, price and portability. The best ones are in the $3-$5,000 range, are designed as lab-grade instruments for big operations, and require careful and regular calibration. They are, however, no more accurate than the LM-1. In fact, because of calibration problems, in many cases expensive analog meters are less precise than the LM-1s 0.01λ accuracy specification.
The Horiba MEXA-700Lambda Meter, which uses an NTK UEGO (wideband) and is in wide use by auto manufacturers, claims only a 0.3 A/F (0.02λ) accuracy at A/F=9.5 (λ=0.65). Another popular meter found in many auto manufacturers' engine development labs is the ETAS LA4 Lambda Meter, which uses a Bosch LSU4 UEGO. Its claimed accuracy is 1.5%, which at 0.7λ (it's richest supported lambda) is about 0.01λ.

When you call Klaus and tell him Rob sent you, also ask how he determined his meter's margin of error and whether he can post his data on the website. :)
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Last edited by Jon [in CT]; 07-18-2003 at 06:50 PM.
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