Hello again,
I want to thank yesterdays attendance in the pipette maintenance / calibration event. Might have been a bit off the hip presentation, but hopefully you atleast got a little understanding how to open the pipettes and how to lubricate the piston that sustains the vacuum and pulls the liquid in the tip. This is likely 50%+ of all the inaccuracy problems, along with drifting on the calibration. It rarely has to do with the springs, but some do have metallic pistons that can bend after which no chance to get it working without changing parts. If you have pipettes that reads numbers way outside the indicated range, then I can try to look into it as it needs to be disassembled completely.
I also showed the rough procedure for the calibration, but I will now provide good resources that will make the calibration easier to understand and to get a more accurate result:
“Pipette Calibration Demonstration complete” on youtube : https://www.youtube.com/watch?v=ZsVSR3oV4Ec Similar to what I showed but more throughout explanation
Sartorius cleaning and decontamination guide: https://www.sartorius.com/download/631518/manual-lh-cleaning-decontamination...
Very detailed guide how to do calibration “PERFORMANCE TEST INSTRUCTIONS FOR BIOHIT PROLINE PIPETTORS”: https://photos.labwrench.com/equipmentManuals/5123-1799.pdf
I would say a rough estimate is to get the pipette at least under 1% error, but in order to really hone it down you would need to account for the temperature with the z-factor, and it accounts for something like 0,3% error. Atleast I have thought that if you can get the error under 1% using density of 1kg / liter instead of 997.5g / liter, then you are within the calibration specifications of maximum of 1,5% error. I would also recommend to quickly check the pipette accuracy with water on a scale before a lot of pipetting, it takes roughly 10 minutes.
I attached a picture to show the calibration screw for the most common pipettes we have, it can be turned with a 3mm hex tool, it should come in the pipette repair kits but I can also provide one. For the older model you can see the calibration screw used in the youtube-video around 10:40 mark.
Thanks a lot for attending and ask if needed, Petri Sundqvist
Lähettäjä: Petri Sundqvist Petri.Sundqvist@oulu.fi Lähetetty: Wednesday, 30 August 2023 8.01 Vastaanottaja: Petri Sundqvist Petri.Sundqvist@oulu.fi; Biolaitos@lists.oulu.fi; bioposti@lists.oulu.fi Aihe: VS: Pipetting repair and calibration tutorial event
Hello everybody,
Sorry for the slight delay in closing of the poll, but the day/time that is leading is Monday 4th at 15:00, which is next weeks Monday. We could meet at the entrance to the molecular labs (B167a) on Monday 4th at 15:00. We will likely use the scale in Tarja’s lab or find some alternative mg/ug scale that we can use for the calibration with water. If you have some own broken pipettes you are welcome to bring those, we have a lot of spare parts for the Biohit/Sartorius pipettes
BR, Petri Sundqvist
Lähettäjä: biolaitos-bounces@lists.oulu.fimailto:biolaitos-bounces@lists.oulu.fi <biolaitos-bounces@lists.oulu.fimailto:biolaitos-bounces@lists.oulu.fi> Puolesta Petri Sundqvist Lähetetty: Wednesday, 23 August 2023 16.39 Vastaanottaja: Biolaitos@lists.oulu.fimailto:Biolaitos@lists.oulu.fi; bioposti@lists.oulu.fimailto:bioposti@lists.oulu.fi Aihe: Re: [Biolaitos] Pipetting repair and calibration tutorial event
Hello everybody,
Just a reminder to vote on the pipette repair tutorial if you are interested, I will close the voting on monday. We will likely disassemble a pipette to see the most common problems and calibrate them using a scale.
BR, Petri Sundqvist
LähetettyOutlook for Androidhttps://aka.ms/AAb9ysg
