Low cost vacuum sensor

[RGV250]

Hi,
I have a need for a cheap hopefully digital output vacuum sensor, I can find quite a lot of positive pressure but only one for vacuum.  https://www.amazon.co.uk/Negative-Pressure-100-0kPa-XGZP6867-Differential/dp/B085MG7VCV  but do not need 5.
I did find what appears to be the same one on ali express but the description was not exactly confidence inspiring.

Bob

[TimB]

What's your definition of low cost and what resolution?

To expand your range search for "absolute pressure sensor" There are a lot of MEMS devices out there that are sub £20

[RGV250]

Thanks Tim,
£20 is around the ball park I was hoping for, resolution does not need to be great, I am just using it for an early warning before I lose the vacuum.
Cannot seem to find a digital output so far but RS seem to have one that fits the bill with analog output for testing.

Bob

[rick.curl]

Hi Bob-
I agree with Tim- A differential sensor can be used to sense a vacuum.  I searched on Digi-key and turned up several that appear to meet your requirements, such as the SPL17-002
If you only need a yes/no answer as to whether the vacuum is working or not, try your local HVAC supplier.  Low- cost pressure (vacuum) switches are used in many gas heaters to verify that the draft inducer is working.

-Rick

[trastikata]

Hello Bob,

Except for barometric pressure sensors, I find analog sensors better option in most applications.

Freescale has bunch of analog vacuum sensors under 10USD (and they send for free up to 15 samples  ).

[ricardourio]

Hi Bob,

   All automotive intake pressure sensors measure vacuum and some positive pressure. For turbo engine you will find up to 4 BAR absolute pressure. There are a lot of it under USD 10, ready with enclosure and external connector if you need it. Unfortunately, almost all signal outputs are variable voltage. Just as example :

https://pt.aliexpress.com/item/1005006314048482.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.1.401fFRb7FRb716&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.354490.0&scm_id=1007.40050.354490.0&scm-url=1007.40050.354490.0&pvid=58b95807-1141-49d1-b877-c4a969b67a73&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40050.354490.0,pvid:58b95807-1141-49d1-b877-c4a969b67a73,tpp_buckets:668%232846%238107%231934&pdp_npi=4%40dis%21BRL%2127.56%2121.49%21%21%2137.80%2129.48%21%402103246617106120017945530e022e%2112000036724605602%21rec%21BR%21106186397%21&utparam-url=scene%3ApcDetailTopMoreOtherSeller%7Cquery_from%3A

Ricardo Urio