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Feature #1285

Updated by tin about 5 years ago

**Computation of the drift rate of calibration constant 72 (will take 1 week to complete): 

 C = [(A – B) * 1000000] / [A * D] ppm per day 

 A = the value of the calibration constant 72 (following an ACAL on day 1 of the test) 
 B = the value of calibration constant 72 (following an ACAL on the last day of the test) 
 C = the drift rate of calibration constant 72 in ppm per day 
 D = the number of test days where the instrument was powered on during the test interval 
 (See Note # 1) 
 If the absolute value of C is > 0.43 ppm per day, then the A3 assembly in your instrument needs to be 
 replaced. 

 *Complete an ACAL just prior to obtaining the present value of Calibration Constant 72* 

 |Date |CAL 72 after ACAL|ppm Deviation|TEMP?| 
 |11/16| 981.648769E-3     |Initial| +41.3°C     | 
 |11/16 +3h| 981.652110E-3     |+0.334| +35.5°C     | 
 |11/17|981.652541E-3      |+0.043|+37.0°C | 
 |11/17 7PM|981.665868E-3      |+1.333|+40.1°C | 
 |11/18|                   |        | 

 |Date |CAL 72 after ACAL|ppm Deviation|TEMP?| Deviation from day 0, ppm | 
 |1/18|997.711415e-03     |    0     | 32.5 | 0 | 
 |1/19|997.711486E-03     | +0.0712 | 31.9 | +0.0712 | 
 |1/20|997.711441E-03     | -0.0451 | 33.8 | +0.0261 | 
 |1/21|997.711391E-03     | -0.0501 | 31.5 | -0.0241 | 
 |1/24|997.711709E-03     | +0.3187 | 30.6 | +0.2947 | 
 |1/25|997.711798E-03     | +0.0892 | 31.9 | +0.3839 | 
 |1/26|997.712097E-03     | +0.2997 | 29.9 | +0.6836 | 
 |1/28|997.711577E-03     | -0.5212 | 32.3 | +0.1624 | 
 |1/29|997.711566E-03     | -0.0110 | 33.0 | +0.1513 | 
 |2/02|997.711546E-03     | -0.0200 | 32.7 | +0.1313 | 
 |2/03|997.711203E-03     | -0.3438 | 34.6 | -0.2125 | 
 |2/04|997.711465E-03     | +0.2626 | 33.4 | +0.0501 | 
 |2/07|997.712158E-03     | +0.6946 | 35.2 | +0.7447 | 
 |2/08|997.712250E-03     | +0.0922 | 34.8 | +0.8369 | 
 |2/09|997.712179E-03     | -0.0712 | 36.4 | +0.7658 | 

 h2. Drift rate : *-0.01623 ppm/day* 

 h2. Drift rate 2 : *-0.03329 ppm/day* (D = 23) 

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