Retrotec DM-2 - Manual (Page 4)

Page 4 of 72
©Retrotec Inc. 2012
To change the European Separator units............................................................................................................ 25
3.1.11 Sig Figs .............................................................................................................................................. 25
To change the number of Significant Figures ...................................................................................................... 25
3.2 Device Setup ...................................................................................................................... 25
3.2.1 Enable and Disable Devices ................................................................................................................... 27
To enable/disable Devices ................................................................................................................................. 27
3.2.2 Enable and Disable Range Configurations .............................................................................................. 27
To enable/disable Flow Range configurations in Device [Setup] ......................................................................... 28
3.3 Mode Setup ....................................................................................................................... 28
To configure Modes: .......................................................................................................................................... 29
4 Understand the Pressure Gauge ....................................................................... 30
4.1 Differential Pressure .......................................................................................................... 30
To measure a pressure ...................................................................................................................................... 30
4.2 Positive vs. Negative Pressure ........................................................................................... 30
Measure a negative pressure ............................................................................................................................. 31
4.3 Analog Magnehelic Gauges ............................................................................................... 31
Retrotec’s magnehelic gauge system (right). ...................................................................................................... 32
5 Reduce Bias pressures, static or fluctuating ..................................................... 33
Reduce fluctuating pressures created by wind .............................................................................. 33
6 Reduce uncertainty in results by taking lots of readings .................................. 35
7 Check your gauge to see if it needs to be sent to factory for re-calibration .... 36
7.1 Verify your gauge calibration between factory calibrations .............................................. 36
To perform a tubing check ................................................................................................................................. 36
To perform a cross port check............................................................................................................................ 37
To perform a T-connection Fan Pressure check .................................................................................................. 38
To perform a syringe check (not as good as the cross-channel check) ................................................................. 38
8 Use the Gauge with a calibrated fan for air leakage testing ............................. 40
8.1 Making the Connections .................................................................................................... 40
8.1.1 Pressure port connections ..................................................................................................................... 40
8.1.2 Control connections .............................................................................................................................. 41
To connect the gauge to a Retrotec fan or variable speed fan drive .................................................................... 41
To connect the gauge to a Minneapolis Model 3 or Model 4 Fan ........................................................................ 42
8.2 Control a fan with the gauge to measure pressure and flow ............................................. 42
To conduct a basic pressure test and ensure your gauge is working .................................................................... 42
8.3 Measure Air Handler flow using Hole Flow on the gauge .................................................. 43
To create an Exhaust Fan Flow Meter ................................................................................................................ 43
9 Troubleshooting ................................................................................................ 45
9.1 Check if moving tubes are causing fluctuating pressure .................................................... 45
To see the effect of a moving tube ..................................................................................................................... 46