What did this man measure?

Absolutely stupid answer.

Routine checks for gas leaks are conducted. This is a requirement of the suppliers/by law xyz. If you have any questions, please contact the regional gas supplier Name ABC. Have a nice day.

And move on.

Brief answer without small talk:

I routinely search for gas leaks. This is a regulation of the suppliers/by law xyz. If you have questions, please contact the regional gas supplier Name ABC. Have a nice day.

And move on.

Exactly that is what one can expect.

Good, at least waterboarding until the little guy tells the full truth!

Absolutely stupid answer.

Simply just "Gas" is also stupid, and therefore: throw the Purch to the Poden! *smile*

Simply "Gas" is also stupid, and teshalp: throws the smoke to the feet! *smile*

It would be more creative to mess up your probe ...

I am missing in the template a "deeply honored property & homeowner" and above all also a worthy closing sentence, perhaps "thank you for your understanding dear Madam/Sir, I will hurry and graciously erase my traces on your valuable land/stone path after completing my humble work."