User manual VAISALA GM K220

[. . . ] 6 Spot checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Two-point calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 CHAPTER 4 TECHNICAL DATA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 VAISALA _____________________________________________________________________________1 User's Guide __________________________________________________________________________ CHAPTER 1 GENERAL INFORMATION Safety Throughout the manual, important safety considerations are highlighted as follows: WARNING Warning alerts you to a serious hazard. [. . . ] Windows® Hyper Terminal) · Power supply, 24 VDC/1A In addition, values on the ambient temperature (with accuracy of ± 0, 5 ºC) and barometric pressure (with accuracy of ± 1 hPa) are needed as input data during the checking or calibration procedure. Requirements for the calibration gases Low end calibration gas N2 gas with a purity of N50 (or better). CO2 concentration shall be 95. . . 105 % of the measuring range of the probe. Traceable to appropriate standards (for example NIST). High end calibration gas VAISALA _____________________________________________________________________________5 User's Guide __________________________________________________________________________ CHAPTER 3 OPERATION Spot checking Spot checking is carried out when there is a need to check if the probe (GMP221 or GMP222) is operating correctly. The reference gas concentration must be within the measuring range of the probe to be checked. Please read requirements concerning the reference gases from Chapter2 Additional equipment before starting the operation. Insert the probe into the chamber (item 5, Figure 1) so that the perforated filter cover is completely inside the chamber 3. Connect the PC to the calibrator with the serial cable (item 8, Figure 1). Check the connection set-up, the serial line settings for data transfer shall be · · · 9600 baud parity: 8/None 1 stop bits 4. Connect the 24 VDC supply power to the connectors (items 9 and 10, Figure 1). The following (or similar) text appears in the terminal window on the PC screen (program version number can be updated): GMT220A - Version: STD 4. 08 Copyright: Vaisala Oyj, 1997-2000 > > 6 __________________________________________________________________________ U421EN-1. 1 Chapter 3_____________________________________________________________________ Operation 6. Let the calibrator settle for 10 minutes. 7. Connect the reference gas and adjust the flow rate to 0. 6 l/min with a screwdriver (item 4, Figure 1). Input the ambient barometric pressure. MF_PRESSURE XXXX<CR> where xxxx= pressure in hPa. Example: >MF_PRESSURE 1013<cr> MF_PRESSURE=1013 > 9. Input the ambient temperature. MF_TEMP XXX<CR> where xxx = temperature is given in tenths of °C (25 °C = 250). MF_MODE 2<CR> Example: >MF_MODE 2<cr> MF_MODE=2 1620. 1 1618. 3 1619. 8 1619. 8 . . . The carbon dioxide concentration (in ppm) is measured every 0. 5 seconds. VAISALA _____________________________________________________________________________7 User's Guide __________________________________________________________________________ 11. The difference between the average reading and the actual concentration of the reference gas shall be within the long term stability specifications of the probe. If there is need for calibration, please refer to the chapter Two- point calibration. Disconnect the gas flow and remove the probe from the chamber. NOTE If the error of the output reading for some reason is more than 20%, please send the probe to Vaisala for service. 8 __________________________________________________________________________ U421EN-1. 1 Chapter 3_____________________________________________________________________ Operation Two-point calibration The reference gases used for the two-point calibration shall represent the low and high end of the probe's measuring range. [. . . ] it has to be given as capital letter (CALICALI L). Example: >CALICALI L 200 0 1013 23<cr> Calibration start - Length is 200 samples (it takes about 107 seconds) You can interrupt operation by CTRL-C 1297. 5 550. 4 382. 7 445. 5 32. 5 1295. 2 554. 5 482. 0 445. 9 32. 5 . . . 1298. 1 561. 7 603. 5 449. 6 32. 5 1296. 9 557. 3 523. 4 454. 2 32. 5 Noise measurement ready Res Avg Res Std FR Avg FR Std Rx Avg Rx Std Tx Avg Tx Std = = = = = = = = 470. 491219 82. 244873 447. 789145 2. 355181 1296. 441917 1. 870829 554. 371452 3. 844639 0 ppm) measurement done. As the calibration at low end is completed, the software asks to change to the high gas. [. . . ]