Too Helpful Employees

I've discovered that one must anticipate the bizarre things employees might do, presented with the opportunity. No, I don't mean the zillion truly stupid things like standing on top of 30' ladders, plugging toasters into an area where flammable vapors accumulate, using a forklift to raise another forklift ... No, I mean the things they'll do in a sincere effort to help you. Or a sincere lack of understanding about what you're trying to accomplish. While performing personal noise exposure monitoring, I have discovered the instructions to the employee when applying the dosimeter must include:

1. Don't share. The employee understood that my primary concern was Machine A. She took the meter off, and gave it to the other worker when switching jobs. She wanted to make sure I found out how loud the machine was by keeping the meter with the worker at the machine.
2. It doesn't record things. Despite the fact that the meter does indeed "record" things, it doesn't actually record what you say. My boss advised this as part of the instructions. I would never have thought of it, but apparently others have.
3. "All day" means "until you leave". A couple employees seemed to either not care or not realize what data are recorded. I down-loaded the data & reviewed the dB v. time. I immediately noticed the last hour of data is 0 (i.e., uniformly less than the threshold). I also immediately realized the employee was not accurate in reporting it had been off for "20 minutes".
4. Have a reason for explaining why you picked on her/him. This week's measurements included a worker in an area already identified as in a hearing conservation program. 3 dB exchange rate or not, there's no way it was going to be less than the previously measured 92 dB. Standing next to a bright blue punch press that is at least 10 times larger than the '53 Plymouth I once owned, and was probably built in the same year, the operator asked rather plaintively, "why did you pick me?" My answer: "because I like blue". That wasn't my real rationale. But, it could have been. The reason was actually because he was the only one operating one of the giant beastie