Oxygen signal: Difference between revisions
No edit summary |
No edit summary |
||
Line 27: | Line 27: | ||
# Check the [[gain]] setting for the affected oxygen channel. Set to Gain 1. | # Check the [[gain]] setting for the affected oxygen channel. Set to Gain 1. | ||
# Apply technical service: [[O2k-Open Support]] | # Apply technical service: [[O2k-Open Support]] | ||
== O2k-Open Support cases == | |||
:::Anonymous user | |||
Question: | |||
Q1: The Oxygen Concentration couldn't go down while I tried zero oxygen calibration. No matter how much solution I added, the oxygen concentration still remain the same. I reassembled, but it still keeps the same. The data is attached. (2019-04-26) | |||
[[File:No_response_to_dithionite.PNG|center|600px]] | |||
Q2: The chamber B's oxygen slope is not stable. This is a new problem I have never seen. Please see the attachment.(2019-04-26) | |||
[[File:Signal_stability.PNG|center|600px]] | |||
Q3. The maximum Oxygen concentration of another Oroboros machine is only about 140. I don't how to increase the starting point of oxygen concentration. (2019-04-25-01) | |||
Answer: | |||
A1: I suspect that the dithionite solution was not correctly prepared or not fresh. Dithionite loses activity quite fast, so you need to make it freshly. Please check this site: http://bioblast.at/index.php/Dithionite | |||
A2: While there is a difference between chambers A and B, the stability of the signal is still within the acceptable range of noise given by the specifications of the instrument, see: [[Oxygen_sensor_test | Oxygen_sensor_test]]. | |||
A3: You may simply need to calibrate, please see here: http://wiki.oroboros.at/index.php/O2_calibration_-_DatLab |
Revision as of 10:03, 15 July 2019
Description
The oxygen signal of the OROBOROS O2k is transmitted from the electrochemical polarographic oxygen sensor (OroboPOS) for each of the two chambers to DatLab. The primary signal is a current [mAmp] which is converted into a voltage [V], and calibrated in SI units for amount of substrance concentration [ยตmol.dm-3 or ยตM].
Reference: MiPNet19.18D O2k-Series G and DatLab 6: Calibration, MiPNet06.03 POS-calibration-SOP
|mitopedia method=Respirometry }}
MitoPedia O2k and high-resolution respirometry: O2k hardware, DatLab
MitoPedia O2k and high-resolution respirometry:
O2k-Open Support
Stability of the oxygen signal
The stability of the oxygen signal of the O2k is evaluated by the (negative) uncorrected slope over time. After smoothing, the slope of a stable sensor should be less than +- 1 pmol.s-1.ml-1 in a 2-ml chamber.
- Instability of the oxygen signal
- There is drift of the oxygen signal over short or long periods of time.
- The signal at air saturation is abnormally high for a given gain setting.
- The zero current is high (>2.5%) and may show drift.
- Follow the standard instructions for oxygen sensor service.
Oxygen signal does not respond
- The oxygen signal remains at or close to zero even at high oxygen levels.
- The signal at air saturation is abnormally low.
- Check the gain setting for the affected oxygen channel. Set to Gain 1.
- Apply technical service: O2k-Open Support
O2k-Open Support cases
- Anonymous user
Question:
Q1: The Oxygen Concentration couldn't go down while I tried zero oxygen calibration. No matter how much solution I added, the oxygen concentration still remain the same. I reassembled, but it still keeps the same. The data is attached. (2019-04-26)
Q2: The chamber B's oxygen slope is not stable. This is a new problem I have never seen. Please see the attachment.(2019-04-26)
Q3. The maximum Oxygen concentration of another Oroboros machine is only about 140. I don't how to increase the starting point of oxygen concentration. (2019-04-25-01)
Answer:
A1: I suspect that the dithionite solution was not correctly prepared or not fresh. Dithionite loses activity quite fast, so you need to make it freshly. Please check this site: http://bioblast.at/index.php/Dithionite
A2: While there is a difference between chambers A and B, the stability of the signal is still within the acceptable range of noise given by the specifications of the instrument, see: Oxygen_sensor_test.
A3: You may simply need to calibrate, please see here: http://wiki.oroboros.at/index.php/O2_calibration_-_DatLab