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Metrohm 726 Titroprocessor User Manual

Page 284

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13.5 Validation / GLP

726 Titroprocessor, Instructions for use

278

278

Sensor test procedure:

After the start of the test the sensor must be immersed in the first buffer

solution (pH 7) within five seconds.

The stirrer is switched on automatically and the potential measured for

three minutes.

The stirrer is then switched off and the potential measured for a further

minute.

The buffer must then be changed (pH 4). By pressing [Next] the same
procedure is started again.

The test data are displayed at the end of the sensor test.

ЪДДД

Sensor test

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД¿

³ ³

³ Meas. input A1 ³

³ Temperature 25.0§C ³

³ ³

³ Buffer ** pH 7.0 ** ** pH 4.0 ** ³

³ time/min U/mV Drift/mV/Min U/mV Drift/mV/Min ³

³ ДДДДДДДДДД ДДДДДДДДДДДДДДДДДДДД ДДДДДДДДДДДДДДДДДДДД ³

³ 1 stirred 0.5 0.2 175.4 -0.4 ³

³ 2 stirred 0.4 0.0 175.3 -0.3 ³

³ 3 stirred 0.3 -0.2 175.2 -0.1 ³

³ 4 0.2 -0.2 175.1 -0.2 ³

³ ³

³ Response time 27.0 s OK 27.0 s OK ³

³ Stream.potent. 0.1 mV OK 0.1 mV OK ³

³ ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД ³

³ ³

³ Slope 0.986 OK ³

³ Zero point (mV) 0.3 mV OK ³

³ pH(as) 7.004 Summary: OK ³

АДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД QUIT ÄÙ

By pressing the [Extend. info] and [Full info] softkeys the test
results of a sensor can be shown again later. The test results of the previous

sensor tests are also shown.

13.5.3 System validation

GLP

GLP

(G

G

ood LLaboratory P

P

ractice) requires the regular checking of the repro-

ducibility and accuracy of analytical instruments by means of standard op-

erating procedures (SOP).

The Titroprocessor 726 should be validated as a complete, integrated titra-

tion system. A series of titrations (titer determinations are best) with primary

standards is recommended. The Titroprocessor can carry out the assess-

ment of the results and monitoring the validation intervals by itself.

In order to take the requirements of your specific applications into account,

the limiting values for the assessment of the reproducibility and accuracy of

the determinations can be individually set.
The validation can be carried out with any determination method which is

stored in the internal memory or on a data card. A simple modification of the

calculation formula will ensure the correct evaluation of the relevant data.