# Gas measurement?

**URL:** <https://community.purpleair.com/t/gas-measurement/2756>\
**Category:** Sensors\
**Created:** [November 18, 2022, 6:02pm UTC](https://community.purpleair.com/t/gas-measurement/2756 "2022-11-18T18:02:08Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![Joanna\_Louie](https://sea2.discourse-cdn.com/flex020/user_avatar/community.purpleair.com/joanna_louie/32/1588_2.png) [@Joanna\_Louie](https://community.purpleair.com/u/Joanna_Louie)\
**Post date:** [November 18, 2022, 6:02pm UTC](https://community.purpleair.com/t/gas-measurement/2756/1 "2022-11-18T18:02:08Z")

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I am looking to buy a purple air monitor. I was looking at the specs for PurpleAir PA-I-LED. The specs say that it has a gas sensor. What gas is the PurpleAir PA-I-LED monitoring? Is the gas sensor for VOCs?

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**Author:** ![Ethan](https://sea2.discourse-cdn.com/flex020/user_avatar/community.purpleair.com/ethan/32/177_2.png) [@Ethan](https://community.purpleair.com/u/Ethan)\
**Post date:** [November 22, 2022, 8:55pm UTC](https://community.purpleair.com/t/gas-measurement/2756/2 "2022-11-22T20:55:48Z")

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Hi @Joanna_Louie, the gas sensor measures total VOCs.

The VOC sensor we use is the BME680 from Bosch. You can view Bosch’s website about it at the following link: [Gas Sensor BME680 | Bosch Sensortec](https://www.bosch-sensortec.com/products/environmental-sensors/gas-sensors/bme680/). That page also includes the sensor’s datasheet.

Currently, the BME680 sensor’s VOC readings are in an experimental phase. We are working on fully understanding the readings and how to implement them into PurpleAir devices properly. You can read more about this at the following link: [BME680 VOC Scale Change on the PurpleAir Map](https://community.purpleair.com/t/bme680-voc-scale-change-on-the-purpleair-map/419).

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**Author:** ![Henry](https://sea2.discourse-cdn.com/flex020/user_avatar/community.purpleair.com/henry/32/2077_2.png) [@Henry](https://community.purpleair.com/u/Henry)\
**Post date:** [February 21, 2023, 11:59pm UTC](https://community.purpleair.com/t/gas-measurement/2756/3 "2023-02-21T23:59:23Z")

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Are the VOC readings still in an experimental phase?

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**Author:** ![Ashley\_PurpleAir](https://sea2.discourse-cdn.com/flex020/user_avatar/community.purpleair.com/ashley_purpleair/32/1661_2.png) [@Ashley\_PurpleAir](https://community.purpleair.com/u/Ashley_PurpleAir)\
**Post date:** [February 23, 2023, 10:12pm UTC](https://community.purpleair.com/t/gas-measurement/2756/4 "2023-02-23T22:12:08Z")

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Hello,

Yes, they are still in the experimental phase. We are finding ways to include everything on the little space available (2MB) on the sensors.

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**Author:** ![saseelig](https://avatars.discourse-cdn.com/v4/letter/s/c68b51/32.png) [@saseelig](https://community.purpleair.com/u/saseelig)\
**Post date:** [May 12, 2023, 12:02pm UTC](https://community.purpleair.com/t/gas-measurement/2756/5 "2023-05-12T12:02:51Z")

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Does the PurpleAir Zen have the BME680 or 688 sensor?

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**Author:** ![jkline](https://avatars.discourse-cdn.com/v4/letter/j/f19dbf/32.png) [@jkline](https://community.purpleair.com/u/jkline)\
**Post date:** [May 12, 2023, 11:30pm UTC](https://community.purpleair.com/t/gas-measurement/2756/6 "2023-05-12T23:30:21Z")

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This page: [PurpleAir Zen Air Quality Monitor](https://www2.purpleair.com/products/purpleair-zen) states that the PurpleAir Zen has the BME688:

- Pressure, Temperature, Humidity & Gas Sensor (BME688)

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**Author:** ![norahm](https://avatars.discourse-cdn.com/v4/letter/n/839c29/32.png) [@norahm](https://community.purpleair.com/u/norahm)\
**Post date:** [July 14, 2025, 8:01pm UTC](https://community.purpleair.com/t/gas-measurement/2756/7 "2025-07-14T20:01:17Z")

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Is the VOC sensor on the indoor air quality monitor still in the experimental phase?