OD measurement influence on OD plot, stirring, and temperature

Using the Pioreactor
1

Experienced some discrepancies while using post/pre delay OD setup:

Turning on the OD measurement:

  1. Some of the Pioreactors stop with pre_delay_duration while others continue to stir without stopping. However, turn-off and turn-on of OD fixes the issue and all the workers stop to obey the pre_delay_duration.

Turning off an on going OD measurement:

  1. The stirring gets more vigorous.
  2. The OD readings jump high and then level off to the initial OD values (picture attached below to illustrate).
  3. The temperature increases slightly, causing the thermostat fluctuations (picture attached bellow to illustrate).

image
image1813×469 135 KB

Did anyone else experienced similar issues?

Pioreactor config.ini setup

[stirring.config]
target_rpm=500
initial_duty_cycle=50
pwm_hz=400
use_rpm=1
duration_between_updates_seconds=23
post_delay_duration=0.25
pre_delay_duration=1.30
# if turning enable_dodging_od on, we recommend decreasing samples_per_second to at most 0.10
enable_dodging_od=True

[od_reading.config]
# how many optical density measurements should be published per second? Recommended maximum is 1.
samples_per_second=0.05

Pioreactor software information
Software version: 25.3.5
Pioreactor models: v1.1

2

hi @sharknaro,

I’m not able to reproduce this locally, but I’ll harden this code for the next release. If you’re able to reproduce this wrong behaviour, I’d be curious about the detailed logs for the worker. (pio logs on the worker, or via the Event Logs → ≡ Detailed view)

3

Actually I just reproduced point 1.

4

Actually I found and fixed both these bugs. ty @sharknaro!

Fixes will be in the next release (very soon).