2000 Fire Door-Fan Manual
updated 2002-05-28
Page 46 of 58
Recalibration of Retrotec Infiltrometer
The NFPA Appendix C requires recalibration of only the room pressure gauge every year. Ask Retrotec for an
exchange 60 Pa. gauge and be sure to specify whether the tubes go out the back for the model 870 “kickstand
model “ or out the side for the model 970 suitcase style. Gauge clip styles all go out the side.
Users of CA2001 software will be supplied with a new calibration file to download that will record the required
date and update your software’s printout of its calibration data.
The NFPA Appendix C requires recalibration of the complete system every 5 years. The entire system must be sent
back for recalibration and checking in our flow chamber. Send back both blowers, low flow plates and console.
Panels don’t need to be returned for the 5-year calibration, but we will check them out if you do send them back.
New certificates will be issued.
Our series 600, 700, 800 and 900 and 2000 flow measurement systems do not require more frequent recalibration
unless they are damaged to the extent that their physical dimensions are changed drastically, or if Field
Calibration Checks repeatedly show that the system is inaccurate.
The measurement method used in our system relies upon the physical dimensions of an annular nozzle which has
well-documented flow characteristics. Flow is proportional to the square root of the pressure drop across the
nozzle. Obvious changes in nozzle size introduce relatively small errors.
We have checked numerous Retrotec Infiltrometers after one (1) year of field use and have never found their
calibration to be out more than the specified accuracy of (+/-) 5 percent.
A quick check of the gauge can be made by "Y" connecting the HOUSE PRESSURE and FLOW PRESSURE gauges
together and elevating the pressure in the common tube to see if they read the same. It should be noted that
similar absolute percent errors in these two gauges cancel each other out to a great extent in a test.
Calibration facility for gauges.
Calibration facility for blowers.