Vaisala DM500 - Manual (Page 7)

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VAISALA ________________________________________________________________________ 5
MI70 LINK PROGRAM............................................................................... 111
Installation ............................................................................ 111
Device Name MI70 ÙDM500 ................................................ 111
Displayed Quantities............................................................ 112
Sensing Unit Status ............................................................. 112
Real-Time Quantities............................................................ 112
Real-Time Update Interval ................................................... 112
Chart ...................................................................................... 112
CHAPTER 18
MAINTENANCE ......................................................................................... 113
Cleaning the Sensor............................................................. 113
Error Messages .................................................................... 115
Technical Support ................................................................ 116
Return Instructions .............................................................. 116
CHAPTER 19
SPECIFICATIONS...................................................................................... 119
Measured Variables.............................................................. 119
Dewpoint Temperature ................................................ 119
External Temperature (Optional) ................................. 121
Integrated Pressure (Optional)..................................... 121
Integrated Flow (Optional) ........................................... 121
General .................................................................................. 121
DMP501 Dewpoint Sensing Unit.................................. 121
Options for DMP501 .................................................... 122
DMI500 User Interface Unit ......................................... 122
Options for DMI500...................................................... 123
Outputs.................................................................................. 123
Electromagnetic Compatibility ........................................... 123
Dimensions (in mm) ............................................................. 123
APPENDIX A
HUMIDITY THEORY................................................................................... 127
Measured and Calculated Results of DM500..................... 127
Water Vapor in Air ................................................................ 127
Saturation Vapor Pressure .................................................. 128
Dewpoint Temperature (T
d
) ................................................. 128
Frost Point Temperature (T
f
) ............................................... 128
Partial Pressure of Water Vapor (P
w
) ................................. 129
Relative Humidity (RH)......................................................... 129
Mixing Ratio (x)..................................................................... 130
Absolute Humidity (a) .......................................................... 131
Absolute Humidity at NTP (aNTP) ...................................... 131
Wet Bulb Temperature ......................................................... 131
Enthalpy (h)........................................................................... 131