Hi Sjoerd,

Tell you boss that Lord Kelvin (1824-1907) was on your side because he said, "When you can measure what you are speaking about and express it in numbers, you know something about it, but when you cannot express it in numbers your knowledge it is the meager and unsatisfactory kind". And if you boss is a man of few words, tell him, "Meten is weten!"

If he still does not want to buy a few of the small data loggers that would allow on-stream temperature measurements in volumes of less than 50 ml, you'll have to perform cost-benefit analysis. Knowledge of sampling and statistics would serve you well at that stage. For example, testing for spatial dependence between temporally ordered temperatures would be required to determine the proper spacing between them. Why don't you ask the supplier of the small data-logger to make a few available and offer to share the test results?

It was H G Wells who believed that statistical thinking would become as important as reading and writing but Wells was an optimist. All the same, statistical thinking may well become important to you!

Kind regards,

Jan W Merks ■

Dear Mr. Theeuwen,

Can you provide more details on what you want to measure and under what specifications and accuracy you need?

Conveoyr Dynamics, Inc. makes data loggers for temperature and humidity. They do not come close to the euro $$ you posted. Then your needs may be significantly greater. ■