Post on 19-Mar-2016
description
Calibration of analysis devices
A matter for specialists• Pure and ultra-pure water: on-site calibration of conductivity/resistivity measurements in accordance with
USP recommendations and the ASTM standard
• Reference solutions directly linked to national and international standards for pH and conductivity measurements
• Metrological competence covering many other parameters (e.g. turbidity, chlorine, dissolved oxygen, nitrate)
Instruments International
Endress+Hauser Instruments International AGKägenstrasse 24153 ReinachSwitzerlandTel. +41 61 715 81 00Fax +41 61 715 25 00http://www.endress.cominfo@ii.endress.com
Other locations
Please visit: www.endress.com/worldwide
IN00107H/29/EN/01.06PF/INDD CS4
sterile
PARA M
MEAS CAL
DIAG
PARA M
MEAS CAL
DIAG
3m max. Sampling valveSampling outlet
Concal reference toolConductivimeter
The importance of analytical measurement is widely recognised in many production sites. These parameters are essential for monitoring the quality of the aqueous solutions used in manufacturing processes.Therefore, to ensure the reproducibility of a pH measurement or of conformity of a conductivity measurement in relation to manufacturing requirements (FDA or European Pharmacopoeia), it is very often necessary to carry out periodically calibration.
Calibration of analysis devices
Conductivity: a specialist matterCalibration of a conductivity measurement chain is usually carried out using an associated reference solution. For values between 0 and 20µS/cm, it is very rare and often impossible to find reference solutions because they become unstable simply by coming into contact with ambient air.
That is why a specific procedure has been defined and described in the ASTM5391 standard, using a comparative measurement against a specific reference system that is linked to international standards. Calibration is carried out by taking a sample equipped with a quick-coupler (e.g. clamp)
Measuring principle Conductivity pH
Place of calibration On-site On-site
Calibration range 0 to 20 µS/cm 70 µS/cm to 2 S/cm 0 to 14 pH
Equipment concerned
Conductivity or resistivity measurement chain
Conductivity measurement chain
pH measurement chain
Calibration method*
By sampling. Comparative measurement
comparative to a reference measurement chain +
control of the transmitter input signals (for USP or
European Pharmacopoeia conformity)
Measurement comparative to a
known conductivity reference solution
Measurement comparative to buffer solutions
Number of calibration points
1 point at the nominal use value
1 point at the reference solution
value2 points
Resources used
• Endress+Hauser reference measurement chain called Concal
• Precision decade box
Accurate solution with temperature
compensation table delivered with quality
certificate
Accurate buffer solutions with
cross table based on
temperature of use
Metrological compliance
To national and international standards
Linking of the solution to the SRM of NIST
To national and international standards
Documents issued
• Calibration certificate• On request, copy of
the proof of conformity to national/international standards
• Calibration certificate• On request, quality
certificate of the reference solutions used
• Calibration certificate• On request, copy of
the proof of conformity to national/international standards
located on the purified water pipe.The procedure applied and the tools used ensure the service is fully compliant with USP requirements stipulated by the FDA or European Pharmacopoeia.
* The calibration method applied in measuring conductivity up to 70µS/cm depends on the type of equipment used (cell constant) and your application (nominal value of the environment measured)