Vaisala DEWCAP DM500 - Page 7

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VAISALA ________________________________________________________________________ 5
MI70 LINK PROGRAM............................................................................... 111
Installation ............................................................................111
Device Name MI70ÙDM500 ................................................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