E8500 Instruction & Operations Manual
version 1.017
Page 26 of 49
value is 0.25. If the thermal efficiency is not known, it may be computed by using the
engine's BSFC (brake-specific fuel consumption-BTU/BHP-HR) as follows:
ENGINE EFFICIENCY = 2547/BSFC
NOTE: Emission measurements in PPM, MGM, #/B and GBH are carried out on a
dry basis as required by the EPA’s 40CFR75 . (The E8500 is an extractive analyzer,
whose conditioning system removes most of the water vapor before the sample
reaches the sensors).
NOTE: MGM (milligrams per cubic meter) units are calculated and displayed for 20C
and 1 atm conditions per US EPA standards.
NOTE: Values of emissions in #/B and GBH are fuel and CO2 dependent.
The fuel parameters for certain typical fuels used in the analyzer (i.e. the F- factors
for anthracite, etc.) have been modified to be identical to those specified in 40CFR60
Appendix A method 19 of the code of federal regulations.
NOTE: NO and NOx emissions in #/B, MGM, and GBH are computed as NO
2
per
US EPA Standards
5) PRESSURE UNITS: The Stack Draft measurement can be shown in inches of water
(inWC), millibar (mbar), millimeters of water (mmWC), or kilopascal (kPa).
1 mbar = 0.10 kPa = 0.40 inWC = 10.2 mmWC
6) CxHy UNITS: The hydrocarbon measurement can be displayed in either % or ppm
units. The factory setting is for % units, and % units are recommended for most
hydrocarbon measurements. The ppm units are only recommended for very low
hydrocarbon measurements.
If using ppm units, an extra autozero calibration should be done within the first few
minutes after the initial autozero calibration has been completed. Additionally, extra
autozero calibrations should be done every 30 to 45 minutes. These extra autozero
calibrations will allow for greater accuracy of the CxHy measurements especially
when measuring in ppm units.
7) O
2
REFERENCE: Many environmental regulations require that the concentrations of
pollutants measured, be corrected to some reference value of oxygen other than the
actual concentration at the time of the measurement. Typical oxygen reference
values are 0% (air free), 3%, 7% or 15%. To select the desired oxygen reference
value, press the
OK
key repeatedly until the blinking cursor is located on the OXY
REFERENCE line on the display, as described above. Toggle the
UP / DOWN
buttons, until the desired value of the reference oxygen is displayed. (Range is 0-
20% in 1% increments). Then press the
OK
key. When the O2 reference is set at
anything other than “TRUE”, the O2 measurement on the display screen will have
reverse contrast (white letters/numbers on dark background). To return to
uncorrected measurements, press the
UP
button until the display reads:
O2 REF: TRUE
