ILPS28QSW o-ring

[nibbler]

Hi,

I'm having a hard time to find a supplier for an o-ring to get the ILPS28QSW sensor waterproof.

In AN5937 ST mentioned they use an o-ring with: ID 1.8mm, thickness 0.5mm (see picture below)

Does anyone here know any supplier who make these, or have used another size with good results? For example if a thickness of 0.75mm would work? I'm afraid the o-ring might be to big?

And FYI: The cylinder formed hole for the sensor is very similar to the one ST is using in AN5937

 O-ring from AN5937:

Dimensions of the ILPS28QSW from the datasheet:

[Federica Bossi · Accepted solution]

Hi @nibbler ,

Welcome to ST Community!

What has been highligted in the AN5937 is an example using NBR  with 70 hardness. It is mandatory don't exceed the limit of internal diamenter (greater than 1.8mm) and o-ring diameter (less than 0.88mm) to avoid to damage the groove of the device. Possible o-ring maker could be: Wurth or O-rings.

[Nick Alexeev]

I'm having the same problem.  AN5937 indeed has the dimensions for the o-ring (see Fig. 3).  1.8mm inner diameter, 0.5mm cross-section diameter.  The smallest standard cross-section diameter is 1mm (from these tables). 

Who makes the appropriate non-standard o-rings?  What o-rings were you using at ST when you were qualifying the sensor?  Please post the suppliers and the part numbers.

[nibbler]

Hi,

I found a supplier in europe, M-seals, who has the o-ring ST suggested: Their p/n: 1017340

FYI, I ended up ordering a custom made o-ring with another material but same dimensions, and at least in my case I had to order at least 250 pcs and the leadtime was 8-10 weeks.

I also found a supplier in the US who also seems to manufacture o-rings in this dimension: https://www.applerubber.com/

For ST:In my opinion you should update AN5937 at page 4

"The following commercial O-ring can be used as a reference..."

Which I find misleading since apparently it is quite hard to find an o-ring in the dimmensions you are suggesting.