# What does -1 mean on my sensor? **URL:** \ **Category:** Bug Reports\ **Created:** [July 21, 2022, 2:40am UTC](https://community.purpleair.com/t/what-does-1-mean-on-my-sensor/1314 "2022-07-21T02:40:05Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![No\_One\_You\_Know](https://sea2.discourse-cdn.com/flex020/user_avatar/community.purpleair.com/no_one_you_know/32/408_2.png) [@No\_One\_You\_Know](https://community.purpleair.com/u/No_One_You_Know)\ **Post date:** [July 21, 2022, 2:40am UTC](https://community.purpleair.com/t/what-does-1-mean-on-my-sensor/1314/1 "2022-07-21T02:40:05Z")
What? -1 on my s4nsor mean? ---
**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:** [July 21, 2022, 2:53pm UTC](https://community.purpleair.com/t/what-does-1-mean-on-my-sensor/1314/2 "2022-07-21T14:53:26Z")
Hi @No_One_You_Know, where are you seeing the -1? ---
**Author:** ![No\_One\_You\_Know](https://sea2.discourse-cdn.com/flex020/user_avatar/community.purpleair.com/no_one_you_know/32/408_2.png) [@No\_One\_You\_Know](https://community.purpleair.com/u/No_One_You_Know)\ **Post date:** [August 8, 2022, 8:15pm UTC](https://community.purpleair.com/t/what-does-1-mean-on-my-sensor/1314/5 "2022-08-08T20:15:20Z")
I am seeing negative one on my purple air map where my house is, why is that. Look on Ballantrae for youself. -1 it says. ---
**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:** [August 9, 2022, 2:40pm UTC](https://community.purpleair.com/t/what-does-1-mean-on-my-sensor/1314/6 "2022-08-09T14:40:11Z")
I believe this is a current bug with the US EPA conversion factor. If you remove the conversion factor, the readings should return to normal. We will look into this.