User manual VAISALA DMT242

[. . . ] Vaisala DRYCAP® Dewpoint Transmitter DMT242 USER'S GUIDE INTRODUCTION June 2008 | M010036EN-D DMT242 is a dewpoint transmitter for wide range of OEM applications. DMT242 measures dewpoint with excellent long term stability which is maintained automatically with the patented auto-calibration procedure. The Vaisala DRYCAP® polymer sensor technology used in DMT242 is also durable against dew in case condenced water exists in the process during system malfunction. [. . . ] Connect the wires to the connector terminals as follows: Terminal nr 1 = V supply + (VAC line) Terminal nr 2 = V supply - (VAC neutral)/signal Terminal nr 3 = Signal + Leave the ground terminal free + Wire colours in cables 221475 and 221476: 1 = brown 2 = blue 3 = black Figure 2 DMT242 Switches Pressu (absolu re te) 1 2 3 4 (bar) 0. . . 2 2. . . 4 4. . . 6 THE SWITCH MARKED WITH 6. . . 8 8 . . . 20 Figure 1 Pressure Setting Table 1 2 3 4 5 6 7 8 = = = = = = = = Cover Connector Flat gasket Counter connector Transmitter body Nut Sealing washer Probe Vaisala DRYCAP® Dewpoint Transmitter DMT242 USER'S GUIDE June 2008 | M010036EN-D 5. Insert the wired screw terminal back into the connector excatly in the position indicated in Figure 3. Insert the wired connector into the counter connector. NOTE The connection is incompatible if the positioning of the screw terminal is NOT as indicated in Figure 3. Install the back cover allowing the cable to run through the hole in the cover. The transmitter is ready for use. NOTE When the power is switched on, wait about 7 minutes before taking measurements. Start-up self-diagnostics freeze the output during the first operation minutes. SCREW TERMINAL MUST BE INSTALLED TO THE CONNECTOR IN THE POSITION OF THE FIGURE (TERMINALS 2 AND 3 AS UPPER EDGE) 1 2 3 4 5 6 7 8 9 Figure 3 Wiring and Installation of Connector CALIBRATION AND MAINTENANCE Replacing the sintered filter = = = = = = = = = Connector Screw terminal of the connector Connector Cable clamp RS-232 serial port Terminals 2 and 3 Three-wire cable Pressure setting switches Fixing screw If the sintered filter is dirty it can prolong the response time of the measurement. If the filter needs to be changed unscrew the filter and replace the old filter with a new one. Calibration It is recommended to perform a calibration check every other year. A field check can be carried out by using a calibrated reference probe and comparing the readings measured with the transmitter and the reference probe. The Vaisala DRYCAP® Hand-Held Dewpoint Meter DM70 is ideal for confirming the performance of the transmitter in the field. By using a connection cable the readings of DMT242 and DM70 can be viewed simultaneously on the display of DM70. If there is need for adjustement contact Vaisala Instruments Service Centers or local Vaisala representative. Vaisala DRYCAP® Dewpoint Transmitter DMT242 USER'S GUIDE June 2008 | M010036EN-D SCALING THE ANALOG OUTPUT VIA THE SERIAL BUS Serial communication settings The analog output scaling can be done using the serial bus and computer with suitable terminal software. Connect the DMT242 to a serial bus via the RS-232 interface by using the following settings: Baud rate: 2400, Parity: none, Data bits: 8, Stop bits: 1. [. . . ] Dewpoint accuracy with DRYCAP® 180M (See figure below) ±2 ºC (±3. 6 ºF) General Sensor Operation voltage Power consumption 24 VDC External load for current output Optional connection cable with DMT242 connector Connector for supply voltage and signal output Max wire size Max wire diameter Service cable for serial line Probe material Sensor protection DRYCAP®180M 17 . . . 28 VAC max 220 mA max 500 2 m or 10 m 0. 75 mm2 6. 5 mm/PG7 DMT242RS stainless steel (AISI 316L) stainless steel sintered filter (HM47280) G1/2" ISO228-1 thread with bonded seal ring (U-seal) plastic (ABS/PC) IP 65 (NEMA 4) -40 . . . +158 ºF) Response time 63 % [90 %] at 20 °C gas temperature at flow rate > 1 l/min and 1 bar pressure: 5 s [10 s] -60 -20 °C Td (-76 -4 °F Td) 45 s [10 min] -20 -60 °C Td (-4 -76 °F Td) DRYCAP® 180S (See figure below) ±2 ºC (±3. 6 ºF) Mechanical connection Electronics housing Housing classification Storage temperature range Complies with EMC standard EN61326-1:1997 + Am1:1998 + Am2:2001; Industrial Environment. Operating Environment Temperature Higher temperature peaks Relative humidity Pressure Sample flow rate 0 . . . [. . . ]