Question about coverslip thickness

[perrywespa]

Several posts have mentioned the critical nature of cover glass thickness. I have a box of 22x40mm labeled as "#1", so I measured a few to see how close they are to the recommended 0.17 inch thickness and got 0.06" on several. Can that be right? I compared to an automotive feeler gauge to be sure I was reading the micrometer correctly.

[PeteM]

0.17mm = about 0.0067 inch.

[Roldorf]

Hmm the .17 on the objective is the size in mm. If you have something different on the objective then that is the size of cover glass you should use.

[mrsonchus]

Sounds like a wrong reading to me, too thin even for a #0 coverslip let alone a #1. The oft-quoted 0.17 seen on objectives is the 'ideal thickness' of coverslips if thickness numer #1.5.

Here are the numbers,

Capture.JPG (27.38 KiB) Viewed 2349 times

[apochronaut]

The specification on the objective is for a cover glass being used over a very thin sample or smear. In reality the specification is a cumulative measure of the sample plus cover glass.

[deBult]

The specification on the objective is for a cover glass being used over a very thin sample or smear. In reality the specification is a cumulative measure of the sample plus cover glass.

Yes: that is why I often use a # 1 (or #0) coverslide when watching pond samples: there is usually some ditritus material in the sample so it has some “thickness” on its own.

[perrywespa]

Brainless here. Must have posted that on a day when I thought "0.17" was inches and not mm. My apologies. Thanks for all the responses that cleared that up!