AverageWhiteBloke
Member
Just bought a TDS/PH/Temp meter off Ebay. Firstly, thought I'd calibrate it before using it just in case it's been sat about in some warehouse for a long time only to find the instructions say to calibrate using 6440ppm standard fluid. I assumed that it made no difference what fluid you calibrated the meter with as long as its accurate.
So, tried the 240ppm fluid I have which gave a higher reading and couldn't get the trimmer to go down low enough, it screwed in so far then starting clicking. Tried again with the 1382ppm I had which to be fair has probably been sat about a bit and again the reading was high and I can't trim it down any further.
Now I'm in a bit of a dilemma, getting hold of 6440ppm standard is the proverbial rocking horse excrement, the only place I could find was wanting nearly £30 inc delivery for 500ml which seems a bit mad saying the meter itself cost less than that.
My other dilemma is that the meter may be faulty and I have no way of knowing without having a calibration fluid to test it to. You would assume though that you should be able to keep adjusting it down regardless of which you have. Anyone know if this is the case or where I could get hold of some 6440 fluid a bit cheaper?
So, tried the 240ppm fluid I have which gave a higher reading and couldn't get the trimmer to go down low enough, it screwed in so far then starting clicking. Tried again with the 1382ppm I had which to be fair has probably been sat about a bit and again the reading was high and I can't trim it down any further.
Now I'm in a bit of a dilemma, getting hold of 6440ppm standard is the proverbial rocking horse excrement, the only place I could find was wanting nearly £30 inc delivery for 500ml which seems a bit mad saying the meter itself cost less than that.
My other dilemma is that the meter may be faulty and I have no way of knowing without having a calibration fluid to test it to. You would assume though that you should be able to keep adjusting it down regardless of which you have. Anyone know if this is the case or where I could get hold of some 6440 fluid a bit cheaper?