[fishbone1]

Hi I am trying to figure out how to measure silcone vapor ppm using a portable device or some method.

I am sorry if this is the wrong location I am a test engineer for an automotive company and need help to how to measure silicone vapor ppm.

[Arkcon]

We're glad to help, but you're going to have to define your application much better than you have.  I can only guess what you may mean:   silicone oil, silicone grease, silicone rubber, silicone resin, and silicone caulk, but none of those is volatile.  Unless you mean solvents and plasticizers used in these, but you'll still have to tell us what.  https://en.wikipedia.org/wiki/Silicone

[Enthalpy]

I can't tell whether portable devices exist already for that. Just some directions:

If silicone is fluorescent, you have a chance to detect a tiny concentration. Concentrate the pumping light to a small air volume, observe only this volume at the fluorescence wavelength(s) typical for silicone. Target the volume from different directions by the source and the detector. Use pulsed light.

Small concentrations in air are often measured by sucking the air volume through a small filter (or a liquid, a sponge...) meant to stop the target molecule. Thanks to the concentrating effect, the target molecule is easier to detect and quantify.