Freeware programmes

Here we offer some EXCEL programmes for quality control charts and for the estimation of measurement uncertainty as well as assisting programmes for the evaluation of PTs.

EXCELKONTROL

Quality control charts are important and helpful tools of internal quality control in analytical laboratories. Therefore they are widely used and required by international standards such as ISO/IEC 17025

ExcelKontrol is a simple Excel® macro, intended for the daily operation of quality control charts in the laboratory.

With ExcelKontrol you may operate x-charts, r-charts, r%-charts, blank charts, differences charts and recovery charts.

All types of charts may be used as Shewhart-charts (with statistically determined limits) or as target charts. In the latter case the limits are defined by external quality requirements independent from the data.

The program is based on the description of quality control charts in the following publications:

• Funk, W., Dammann, V. and Donnevert, G., 2007. Quality Assurance in Analycal Chemistry. 2. Auflage, Wiley-VCH, Weinheim
• ISO 7870-2 Control charts.
• NORDTEST, 2011. Internal Quality Control – Handbook for Chemical Laboratories. NORDTEST Report TR 569, available here

System requirements
Microsoft Excel 2007 or later

Author: Dr.-Ing. Michael Koch

Copyright: This program is subject to the copyright of the author. It may be freely copied and distributed, as long as the copyright notice is not removed.

Warranty and liability: This software is provided "as-is," without any expressed or implied warranty.
In no event shall the author be held liable for any damages arising from the
use of this software.

Improvement of the program: If you have suggestions for improvement of the program or you want to report bugs, you are invited to contact the authors. We gratefully acknowledge any support.

Save the file ExcelKontrol_2.4_setup_en.zip to your computer. The file must be unzipped, then you may install the programm with a double click on "ExcelKontrol_2.4_setup_en.exe". Please consider the EXCEL macro security options for the excution of EXCEL macros. You will find more details in the info text shown during installation or in the manual.

ExcelKontrol is available in German as well as in English.

• EXCELKONTROL 2.4
  • german
  • english

Estimation of measurement uncertainty from validation and quality control data

• In the NORDTEST- Handbook for calculation of measurement uncertainty in environmental laboratories as well as in ISO 11352 on the estimation of measurement uncertainty based on validation and quality control data a procedure for the estimation of measurement uncertainties is presented. We have implemented these calculations in an EXCEL workbook. At present two versions are available:
  • Calculation of absolute measurement uncertainty >> mu11352_abs_en_v2.31.xltx
  • Calculation of relative measurement uncertainty >> mu11352_rel_en_v2.31.xltx

Estimation of uncertainty from sampling

• In the Eurachem guide "Measurement uncertainty arising from sampling - A guide to methods and approaches" the so-called "duplicate method" for the estimation of sampling precision is described. We have implemented these calculations in an EXCEL Workbook. >> MU_sampling_v1.2.xltx. For the validation of this EXCEL-Workbookyou may findhere a version with example data A1 from the Eurachem Guide.

Assisting programmes for the evaluation of PTs

• Homogeneity check according to ISO 13528:2015 >> homogeneity_ISO_13528_2015_v2.xlsx
• Calculation of kernel density distributions >> kerneldensity_v3.xlt
• Calculation of a robust mean according to algorithm A (ISO 5725-5 and ISO 13528 resp.) >> AlgA.xltm
• Demonstration of the principle of algorithm A >> AlgA_demo.xls
• Q_n method for the estimation of standard deviation >> QN.xlsm
• Bootstrapping calculation of standard error of arith. mean, median and algorithm A >> bootstrap_for_arithm_mean_-_median_-_and_AlgA.xlsm

If you have questions regarding these programmes, please do not hesitate to contact us.