# Start up question - OD readings **URL:** \ **Category:** Getting Started\ **Created:** [November 16, 2023, 7:20pm UTC](https://www.evolver.bio/t/start-up-question-od-readings/495 "2023-11-16T19:20:27Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![bgwong](https://yyz1.discourse-cdn.com/flex035/user_avatar/www.evolver.bio/bgwong/32/262_2.png) [@bgwong](https://www.evolver.bio/u/bgwong)\ **Post date:** [November 30, 2023, 9:38pm UTC](https://www.evolver.bio/t/start-up-question-od-readings/495/4 "2023-11-30T21:38:21Z")
Hi, More information description on this can be found here: > [@OD measurements with two photodiodes?](https://www.evolver.bio/t/od-measurements-with-two-photodiodes/99): > > Summary I’m looking for some advice on how to properly do calibrations with two variables. Background I’m trying to integrate hardware configuration for OD measurements to improve the consistency and dynamic range of the sensors. I figured adding a different sensor at a different LED-diode offset would do the trick. I did a simple, rough experiment and collected measurements off of 90 degree and 135 degree offsets with increasing amount of milk (to approximate scattering from cells). Heres t… The TLDR is that it depends on what OD range you are looking to run your experiment in. Brandon --- _[View the full topic](https://www.evolver.bio/t/start-up-question-od-readings/495)._