Download MODEL 602 BETAPLUS
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7.4 MASS MEASUREMENT SYSTEM CALIBRATION CHECK (Beta Span Test) Periodic calibration of the instrument is not required, but instrument failure or measurement errors may indicate that one or more components (the Geiger-Müller detector and/or associated electronics) need to be replaced. The calibration function determined during the final acceptance test will always remain valid over the Geiger-Müller (GM) detector’s lifetime. Under operating conditions proper implementation of the measurement procedure and accuracy of the calibration function are guaranteed by the implemented quality controls (see section 2.6 “QC Mass Measurement System Calibration”). The instrument can automatically perform a ß calibration check (Beta span test) by measuring alternately the ß flux in air and the ß flux passing through the reference aluminum membranes. The calculated mass thickness values of the two membranes, are compared with their associated nominal values. The test gives the calculated mass thickness values and the percentage deviations from the respective nominal values. 7.4.1 Starting the test (STATUS: Sampling) At the beginning of every operating cycle the instrument automatically performs the beta span test (see section 2.6 “QC Mass Measurement System Calibration”). The beta span test can even be performed during the normal sampling and measurement cycles without stopping the operating cycles. Following the procedure described below, it is possible to choose whether the instrument will be programmed to perform the beta span test at the beginning of the following mass measurement cycle. - With the instrument in SAMPLING Status, press and hold the ESC key for at least 5 seconds to access the Menu code (access to support tools). - Enter code 951 using the Select keys and press ENTER to access the function that activates or deactivates the beta span test at the beginning of the next sampling cycle. - Using the YES/NO keys, select “ON” to activate the test or “OFF” to deactivate it and press ENTER to confirm. If “ON” is selected, the beta span test will be performed only at the beginning of the cycle following the current sampling cycle. 04/05/06 12:30:00 < 03/05/06 15:27:12 Status :SAMPLING ENTER for menu Press ESC and hold for at least 5 sec. Menu code: 000 Menu code: 951 ENTER Beta test activation: OFF NOTE 1: the test takes 10 minutes in Hourly Mode and 25 minutes in Multi-Time Mode. That time will be deducted from the programmed sampling time (timing) of the cycle in progress NOTE 2: In Hourly Mode the test is performed only if a blank session is not expected during the cycle. 134 ON OFF ENTER 04/05/06 12:30:00 Status :SAMPLING < 03/05/06 15:28:15 ENTER for menu