Buffer Quality Control Certificate

For the calibration of the value of our buffer or electrolyte solutions, the potentiometric measuring instruments were calibrated using one or two different reference buffer or electrolyte solutions, based on primary reference materials of the NIST2

The National Metrology Institutes compare their measurement capabilities periodically in key comparisons within the "Mutual Recognition Arrangement of National Measurement Standards and of Calibration Certificates issued by National Metrology Institutes (CIPM-MRA)". The international comparability, harmonization and the equivalence of their measurement capabilities are therefore ensured.This guarantees a flawless traceability of the certified pH buffer values to NIST along with our Quality Management System. The certification is done for each lot.

pH Buffer Solution

Actual pH Value

12

Date of Certificate Issue

Nominal Specifications

Buffer Properties

Traceability

51300193, 51300194, 51340230

The expanded uncertainty (k = 2) of the measurement is 0,02 pHNational Institute of Standards and Technology, Geithersburg, USA

Buffer pH 9.21

January 16, 2010

January 16, 2008

di-Sodium tetraborate decahydrate

9.22

1T016A

Secondary pH Reference Material

191-I-C

10.012 +/- 0.006 (25°C)

Quality Control

Order number

Procedure

Buffer Substances

Lot No. Solution

Expiry DateProduction Date

Two point calibration

Alfons Meier

January 16, 2008

Lot No SRM (NIST) 191-II-C

NIST Standard solution value 9.182 +/- 0.005 (25°C)

187d

Sodium Carbonate Sodium Bicarbonate Sodium Tetraborat

Decahydrate (Borax)

1