User manual VAISALA HMP140A

[. . . ] USER'S GUIDE Vaisala HUMICAP Humidity Transmitter Series HMP140A U175EN15 PUBLISHED BY Vaisala Oyj P. O. Box 26 FIN-00421 Helsinki Finland Phone (int. ): +358 9 8949 1 Fax: +358 9 8949 2227 Visit our Internet pages at http://www. vaisala. com/ Vaisala 2006 No part of this manual may be reproduced in any form or by any means, electronic or mechanical (including photocopying), nor may its contents be communicated to a third party without prior written permission of the copyright holder. The contents are subject to change without prior notice. Please observe that this manual does not create any legally binding obligations for Vaisala towards the customer or end user. All legally binding commitments and agreements are included exclusively in the applicable supply contract or Conditions of Sale. U175en-1. 5 HMP140A SERIES Operating Manual Contents 1. [. . . ] Any contaminated water condensing on the sensor may shorten its life span and change the calibration. 10 9 8 7 dRH (%RH) 6 5 4 3 2 1 0 -40 -20 0 20 40 60 80 100 Temperature (C) Figure 2. 1 Measurement error at 100 %RH when the temperature difference between the ambient and the sensor is 1 C 2 1999-12-08 U175en-1. 5 HMP140A SERIES Operating Manual 3. 3. 1 INSTALLATION Selecting the place of installation Select a place that gives a true picture of the environment or process and is as clean as possible. Air should circulate freely around the sensor. A rapid air flow is recommended as it ensures the same temperature for the ambient air and the sensor head. Install the transmitter in a place where no cold or hot spot can develop. If the sensor head is installed in a duct or channel where the temperature is different from the ambient temperature, insulate the point of entry; this is particularly important if the transmitter is installed with the sensor head pointing downwards. Vertical installation of the HMP142A and HMP143A is not recommended; they should be mounted with the sensor head horizontally whenever possible. An uninsulated installation might lead to condensation on the sensor head and even if no condensation occurs, the resultant air flow may change the temperature near the sensor head and distort the readings. 3. 2 Mounting The electronics of the HMP140A series can be disconnected for ease of installation and service. The housing can be conveniently installed and the electronics then consequently mounted. For service and maintenance purposes the electronics can be disconnected without disconnecting the cabling, and taken to an appropriate environment for necessary adjustments. 60 6. 5 83. 5 60 4. 2 Figure 3 1999-12-08 Drilling dimensions (in mm) 3 HMP140A SERIES Operating Manual U175en-1. 5 3. 2. 1 Mounting the HMP141A The optimal installation of the HMP141A is with the sensor head pointing downwards. Upward mounting should be avoided due to internal heat transfer. 1. Mounting and wiring: cable feedthrough on the surface or in the connection box. Mount the protection lid to the connection box. Push the sensor head through the protection lid as in figure and connect the electronics housing to the connection box. Make sure that the pins at the bottom of the electronics housing are in contact with the screw terminal. Fasten the four connecting screws of the electronics housing. Place the sensor head into the protection lid. Close the cover and fasten the two connection screws. 4 1 6 4 4 4 5 2 3 Figure 3. 2. 1 3. 2. 2 Mounting of the HMP141A Mounting the HMP142A The HMP142A transmitter should be mounted with the sensor head horizontally whenever possible. This way, any water that might condense on the tube cannot flow on to the sensors. When there is no alternative but to install the sensor head in the process vertically, the point of entry must be carefully insulated. 4 1999-12-08 U175en-1. 5 HMP140A SERIES Operating Manual 225 15 12 Figure 3. 2. 2 3. 2. 3 Dimensions of the HMP142A (in mm) Mounting the HMP143A The cable model HMP143A should also be mounted with the sensor head horizontally whenever possible. This model is provided with two plastic nuts and a gasket. Mount the nuts on the sensor head: disconnect the cable from the transmitter, insert the nuts and fasten them on the sensor head. A mounting flange is also available (see Fig. [. . . ] The maximum error in output without recalibration is 0. 5 %FS. 1999-12-08 1 U175en-1. 5 HMP140A SERIES Appendix 2 APPENDIX 2: SETTINGS OF THE LOCAL DISPLAY F RH/T C Figure 1 Location of the RH/T button and the C/F jumpers The reading on the local display (relative humidity or temperature) can be chosen by pressing the RH/T button beside the display. At power-up, the display always shows the relative humidity reading. This can be changed to temperature reading by pressing the RH/T button once. Further pressings will change the reading between RH and T. [. . . ]