Retrotec DM32X - Page 6

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© Retrotec 2022
8.9.3. Let Time Averaging take effect before making readings ....................................................... 53
8.9.4. Use Baseline feature to reduce the effects of a constant wind ............................................ 53
9. Technical Specifications ................................................................................. 55
Appendix A: Understanding Pressures on the Gauge ........................................... 57
Differential Pressure .................................................................................................................................... 57
Positive vs. Negative Pressure ..................................................................................................................... 57
Why static and fluctuating pressures occur, causing bias ........................................................................... 58
Managing fluctuating pressures created by wind ....................................................................................... 58
Reduce uncertainty in results by taking lots of readings............................................................................. 59
Appendix B: Flow Equations used with Devices ................................................... 60
Appendix C: Manually estimate Flow if required test pressure cannot be reached
............................................................................................................................ 65
Cannot Reach 50 Pa Factors ........................................................................................................................ 66
Cannot Reach 25 Pa Factors ........................................................................................................................ 67
Appendix D: Details about the @Pressure extrapolation function ....................... 68
“n value” for @Pressure extrapolation ....................................................................................................... 69
Errors occur in estimated flow if gauge and actual “n” don’t match .......................................................... 70
Appendix E: Tables to adjust Flow values for temperature difference ................. 73
Appendix F: Tables to correct Flow if range selected did not match the installed
range ................................................................................................................... 75
Appendix G: Measure Supply or Exhaust flow with a gauge and box .................. 76
Glossary ............................................................................................................... 78