Factory Pro 4 gas and 5 gas EGA calibration
The base calibration has been set at the EGA
bench manufacturer's facility.
They say that it should never need to be reset.
We've found that to be mostly true.
However, here's how to calibrate the bench.
requires:
Calibration gas: typically BAR 97 HIGH
500ml/m regulator
host6800.exe program
- Cal gas: Bar 97 HIGH
- for 4 gas
- use "BAR 97 HIGH" which is
composed of:
- propane HC
3200ppm
- co%
8%
- co2%
12%
- for 5 gas (w NOx)
- use "BAR 97 HIGH with NO"
which is composed of:
- propane HC
3200ppm
- co%
8%
- co2%
12%
- no
3000ppm
- If BAR 97 HIGH is not available, it is ok to
use a similar composition of test gases - The
calibration program allows you to enter the %
and ppm values of what you are using. You can
easily use BAR 97 MID, The program will
interpolate and extrapolate a slope.
............................................................
- Calibration:
- HOST6800.exe: Start this program.
- EGA bench: power up and leave exhaust probe in fresh air -
let warm up for 20 to 30 minutes.
- Port Select: Check box in port that EGA is using.
- Click on STATUS and drag popup window away from HOST6600
window. (to check and monitor EGA function).
- Click START (to start automatic digital gas readings)
- Note gas reading display, refreshing at set intervals.
- Click ZERO. It's the regular "zero" routine -
exh probe to fresh air
- CO=about 0%,
- HC=about 0ppm, (actual atmospheric is
still .039% or 1/25th of 1% by volume)
- CO2=about 0%,
- O2=about 20.9%, (actual atmospheric O2
is ~20.946%)
- NOx= about 0 ppm
- Connect "BAR 97" calibration gas to bench inlet.
- Click on Bench command: #3 SPAN CALIBRATION, SPAN window pops up
- Check gases you want to calibrate with "BAR 97" calibration
gas and add expected values from bottle label or as
noted. Just add the value and not the "%" or "ppm".
For example with BAR 97 HIGH gas:
- Click CO and enter "8"
- Click CO2 and enter "12"
- Don't click O2 as O2 is zero in cal gas - calibrate
separately to ambient air. (Is
my o2 sensor bad?)
- When calibrating gases, you cannot
enter decimal values, so, if you
were calibrating O2, O2 is
entered as "21". instead of
20.9. The software might
compensate internally.
- Special Note for HC
- SOFTWARE ISSUE: In the
HOST6800 software, click HC and enter of
1/2 the cal gas stated,
as in if the bottle says 1200,
enter 600, Have to do that
regardless of cal gas selection
(propane or hexane) If you do
that, the digital readout, which
has been running all this time
in the background, will read
correctly.
- Only if you have NO(x),
click NO(x) and enter "3000"
- Open calibration gas regulator to 500ml/m.
.
- Click SEND, then watch the digital display change (a few
seconds later)
- Verify that digital readout matches cal gas values.
- Close calibration gas.
- Now, oddly, if you have just installed a new NOx sensor,
AFTER YOU CALIBRATE NO(x), go
to Bench commands and click on #10 "New NO sensor". Seems more
logical to tell the software that it's a new NO sensor before
you calibrate, but
that's the way the software was written years ago.
- Note Host6600 digital readings, close Host6800
program, connect EGA pumps and start dyno software and ZERO ega.
http://www.bridgeanalyzers.com/EGA/Automotive/mediaRepos/productDocs/White%20Paper%204.pdf
for excellent overview of Bridge and other analyzers, by Robert Schraeder