User manual VAISALA PTB330TS

[. . . ] USER'S GUIDE Vaisala Barometric Pressure Transfer Standard PTB330TS M210983EN-A PUBLISHED BY Vaisala Oyj P. O. Box 26 FI-00421 Helsinki Finland Visit our Internet pages at http://www. vaisala. com/ © Vaisala 2009 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. [. . . ] It is recommended that calibration and adjustment should be carried out by Vaisala. Users can calibrate the PTB330 barometer using serial port commands. Using the service port is recommended; see section Connecting to the Serial Line on page 61. The calibration and adjustment procedure, as well as the calibration commands, are described in section Calibration and Adjustment of PTB330 on page 45. The HMP155 can be adjusted using the MI70 indicator, or through the serial port. This document explains the adjustment using the MI70 indicator. For instructions on using the serial port, refer to the HMP155 User's Guide. 44 ___________________________________________________________________M210983EN-A Chapter 4 ______________________________________________________________ Maintenance Calibration and Adjustment of PTB330 In PTB330, the raw measured pressure value of each barometer module is first corrected using the corresponding multipoint adjustment values. The additional linear adjustment (if enabled) is applied to the corrected values. This allows the user to fine-tune the pressure reading using the linear adjustment without performing a complete readjustment for the barometer module, see Figure 20 on page 45. 0708-053 Figure 20 PTB330 Adjustments To measure new adjustment values and perform the actual adjustment, first disable the corresponding adjustment on each barometer module you are going to adjust (see the procedure above). If you are going to perform a multipoint adjustment, disable also the linear adjustments. If you are going to do only a linear adjustment, leave the multipoint adjustments untouched. After disabling the previous adjustments, calibrate the PTB330 against your pressure reference. Make a note of the pressure reading of each PTB330 barometer module separately (quantities P1, P2, and P3). Then use the display/keypad to enter and activate the new multipoint/linear adjustment factors. NOTE Making adjustments is possible only after adjustments have been unlocked. To unlock the adjustment menu, press the ADJ button on the motherboard of the transmitter. The user can select a simple offset or a two-point offset and gain adjustment and use the LCP command for adjustment of the barometer module. The MPCP command is used for the more sophisticated multipoint correction capability at up to eight pressure levels. Check first what linear corrections the transmitter is currently using before VAISALA _______________________________________________________________________ 45 User's Guide ______________________________________________________________________ attempting to readjust the barometer module. As the previous linear corrections will disappear when new linear corrections are input, the user has to take into account the previous linear corrections when deciding about the new ones. NOTE Entering new linear or multipoint corrections will always cancel the previous corrections. It is advisable to write down the previous linear and multipoint corrections so that they will not be lost by mistake. Table 7 Command LCP1 ON/OFF LCP1 MPCP1 ON/OFF MPCP1 CDATE CTEXT Adjustment and Calibration Commands for Module P1 Function Enables/Disables the linear corrections Enter linear corrections Enables/Disables the multipoint corrections Enters multipoint corrections Shows or sets the calibration date Shows or sets the calibration info text. Opening and Closing the Adjustment Mode The adjustment mode has to be available before you can proceed with the adjustment and calibration. The adjustment button with indicator LED is located in the upper corner on the left-hand side of the motherboard. [. . . ] After the reset, the user port switches to start-up output mode selected with command SMODE. Example: >reset PTB330 / 1. 04 > VERS Use the command VERS to display software version information. Example: >vers PTB330 / 1. 04 > 78 ___________________________________________________________________M210983EN-A Chapter 7 ____________________________________________________________ Technical Data CHAPTER 7 TECHNICAL DATA This chapter provides the technical data of the PTB330TS. These specifications apply when MI70, PTB330 and HMP155 are used together in the PTB330TS product. [. . . ]