David Edwards
Member
As title says, any recommendations - appear to be loads on Amazon.
Thanks
Thanks
You need to buy a meter with "2 point calibration" and the buffers (pH4, pH7 and pH10) to calibrate the meter.As title says, any recommendations - appear to be loads on Amazon.Thanks
Either the Hanna 98100 or 98103 are both accurate and easy to use.
I got the 98100 but unsure if you need the .01 PH so if I was to get another I might just get the 98103 and settle for .1 PH reading.
http://www.hannainstruments.co.uk/parameters/ph/testers.html
Replaceable Electrode – No need to replace the whole meter when the electrode needs replacing. Spare and replacement electrodes are available for this product.
Hi Andrew,Either the Hanna 98100 or 98103 are both accurate and easy to use.
I got the 98100 but unsure if you need the .01 PH so if I was to get another I might just get the 98103 and settle for .1 PH reading.
http://www.hannainstruments.co.uk/parameters/ph/testers.html
Yes, you need both the buffers and the storage solution.Clicking onto the website it suggests 2 other products to buy, namely combination buffer solution and storage solution - are these essential items - the latter suggests it might be?
You could be right or wrong.Surely a cheaper probe would do for a PH profile for co2? it might read the wrong PH but it would still read the 1.0 drop? or am i just completely wrong?
Surely a cheaper probe would do for a PH profile for co2? it might read the wrong PH but it would still read the 1.0 drop? or am i just completely wrong?
I tried CO² in aquarium for only 2 years and when the gas ran out never bothered to buy any new gas. I'm to much of a buddhist for CO², not a race car fan, i'm an oldtimer fan. Rather patiently enjoy the ride in a slow pace and gently sway around the complications. The journey is more important than the destination.
But in my vegtable gardening history i collected quite a few pH meters i could play with during this time. Few newly both and a few on the used market, i still have the Milwaukee and the Hanna and a few cheaper brands i don;t rmember what brand they are, total about 5 of them, could be 6 if i do a search.. And each meter has it's issues and limitations by it's own. And funny is even if all calibrated correctly with the very same calibration method still non of them showed the excact same valua measuring a solution that was more than 1 point away from it's calibration point. There always was a deviation in the reading.. Iniminimynimo and picked the most expensive one and hope it's the most accurate.
Actualy i never gave it much thought about how these things function, it was here at UKAPS i learned that for the first time.. Did some more reading into it and actualy they are awfully simple volt meter devices. I also learned to understand some simple and obvious pH measuring basics that are a bit shrouded in mystery in the general consensus by the users because it's for technical viewpoint and likely other conveniences not fully correctly explained in the manuals.
Since they all have a percantage accuracy deviations is the reason what makes calibration important. The further away you measure from your target calibration the more this deviation obviously will be. Thus it makes sense to take this into account while calibrating.. If you calibrate 7 and your target value is near 4, you will have the maximun deviation the device can give. In this case you should calibrate 4 to have the minimum deviation.Makes sense doesn't it? If for example the inaccuraty is 1% than 1% of 3 is greater than 1% of 0,5. That's relatively simple.
What in this case doesn't make sense is why you always should do a 2 point calibration?. Because the devices accury discrepancy depends on your last calibration target. If your pH target is pH 6.8 than calibrating pH4 doesn't make any sense because you calibrate almost 3 points away from your target. (1% of 3 is greater than 1% of 0,5).
Calibrating is simple resetting the device to it's nearest target.
Why even manufacturers still claim you always should do a 2 point calibration to be more accurate is a technical and mathematical mystery to me that probably has more to do with pH4 calibration fluid shelf life. Ph4 is the most unlikely target generaly used, who needs that value anyway if your not Dexter, ore a crop grower that needs pH 5?
Thanks again for the lessons guys.