# OD calibration Using Standards

**URL:** <https://forum.pioreactor.com/t/od-calibration-using-standards/491>\
**Category:** Software\
**Tags:** feature\
**Created:** [October 10, 2024, 4:24pm UTC](https://forum.pioreactor.com/t/od-calibration-using-standards/491 "2024-10-10T16:24:16Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![DocRuzzy](https://forum.pioreactor.com/user_avatar/forum.pioreactor.com/docruzzy/32/343_2.png) [@DocRuzzy](https://forum.pioreactor.com/u/DocRuzzy)\
**Post date:** [October 10, 2024, 4:24pm UTC](https://forum.pioreactor.com/t/od-calibration-using-standards/491/1 "2024-10-10T16:24:17Z")

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I find the current method of OD calibration to be fairly time consuming, especially if calibrating multiple reactors.

What I want to do is have a set of standard 20ml vials with known OD readings. I just want to be able to say I’ve got 5 standards, go through put in the reference OD and then take the reading.

I’m not sure how well this is going to work using Impranil instead of cells, but it is probably better than not calibrating, and much simpler with no time dependence.

I’ve revised the od\_calibration.py, but I don’t know where to put it. It is supposed to function just like the old one, but can be called with pio run od\_calibration stdcal

Could you please advise how to replace the original od\_calibration.py?

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**Author:** ![CamDavidsonPilon](https://forum.pioreactor.com/user_avatar/forum.pioreactor.com/camdavidsonpilon/32/3_2.png) [@CamDavidsonPilon](https://forum.pioreactor.com/u/CamDavidsonPilon)\
**Post date:** [October 10, 2024, 8:36pm UTC](https://forum.pioreactor.com/t/od-calibration-using-standards/491/2 "2024-10-10T20:36:27Z")

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We developed the routine with 1 pioreactor and 1 vial in mind. But yes, you can probably think of better ways. There was a community contribution to use standards: [GitHub - odcambc/od\_standards\_calibration\_plugin: An plugin for Pioreactors that allows OD calibration from a set of standards.](https://github.com/odcambc/od_standards_calibration_plugin), but I’ve never tried it!

> Could you please advise how to replace the original od\_calibration.py?

You can put this in the `~/.pioreactor/plugins` folder, and it should replace the existing code when you run `pio run od_calibrations`.