- #1
rwooduk
- 762
- 59
If anyone has used or uses an oxygen meter and could offer some advice it would be greatly appreciated.
I degassed a solution of potassium iodide for 10 minutes each time and did experiments. However to get a more accurate measurement of the amount of O2 present I've decided to use an oxgen meter.
At the same time I am degassing phenol solution and need to do experiments at the same oxygen content as the potassium iodide used in previous experiments.
Q1. the oxgen meter takes a LONG time to stabilise when taking a measurement of degassed solution. It decreases rapidly then decreases slowly until it reaches a minimum value. Is this normal? And am I correct in taking the minimum value it gives i.e. the oxygen probe won't cause further degassing so the minimum value it gives must be the closest value to the truest value.
Q2. for the potassium iodide solution, I have dissolved 16g KI in one litre of distilled water. Am I correct in setting the Salinity value of the meter to 16g/L?
Q3. if i degas 400ml potassium iodide for 10 minutes i get an oxygen value of around 13%. If I degas 750ml of phenol solution (not a salt) for 10 minutes I get an oxgen value of around 10%. Shouldnt the potassium iodide solution hold LESS oxygen because its a salt?
Q4. the idea was to test the oxygen content of the potassium iodide solution after 10 minutes degassing (because I have done this in previous experiments) and THEN make a calibration curve of degas time vs oxygen content for the phenol solution. Which I can then use to decide how long to degas the phenol for to achieve the same oxygen content as I had with the KI solution. HOWEVER the curve isn't linear it decreases rapidly with degas time and then flattens out when the solution becomes full degassed. So how would I go about doing this?
If anyone can make any suggestions regarding one or more of the above questions it would really help our project move forward!
I degassed a solution of potassium iodide for 10 minutes each time and did experiments. However to get a more accurate measurement of the amount of O2 present I've decided to use an oxgen meter.
At the same time I am degassing phenol solution and need to do experiments at the same oxygen content as the potassium iodide used in previous experiments.
Q1. the oxgen meter takes a LONG time to stabilise when taking a measurement of degassed solution. It decreases rapidly then decreases slowly until it reaches a minimum value. Is this normal? And am I correct in taking the minimum value it gives i.e. the oxygen probe won't cause further degassing so the minimum value it gives must be the closest value to the truest value.
Q2. for the potassium iodide solution, I have dissolved 16g KI in one litre of distilled water. Am I correct in setting the Salinity value of the meter to 16g/L?
Q3. if i degas 400ml potassium iodide for 10 minutes i get an oxygen value of around 13%. If I degas 750ml of phenol solution (not a salt) for 10 minutes I get an oxgen value of around 10%. Shouldnt the potassium iodide solution hold LESS oxygen because its a salt?
Q4. the idea was to test the oxygen content of the potassium iodide solution after 10 minutes degassing (because I have done this in previous experiments) and THEN make a calibration curve of degas time vs oxygen content for the phenol solution. Which I can then use to decide how long to degas the phenol for to achieve the same oxygen content as I had with the KI solution. HOWEVER the curve isn't linear it decreases rapidly with degas time and then flattens out when the solution becomes full degassed. So how would I go about doing this?
If anyone can make any suggestions regarding one or more of the above questions it would really help our project move forward!