DO meter selection

[Kristine Allouchery]

'm doing some research into digital DO meters and have found 2 that both seem reasonable.  However, I've never used one before so I'm wondering if anyone has insight as to the appropriate tool for the job.  We are planning to run a 2,000 gallon system.

One is the YSI Professional Series Instrument - it's a bit cost prohibitive through Pentair, at around $985.

The other is the Hanna Instrument HI 9147 for $347, direct from the manufacturer.

Price disparity is rather broad, so I'm wondering what the most important components should be when making the selection.

Thank you!

[Glenn]

Scott, I misplaced the first cap shortly after purchase and began using the second. We found the misplaced one soon after and following my son's suggestion soaked it in hard contact lens solution, rinsed thoroughly and stored it in a vial filled with the solution it came with.  About 20 months later now, I just checked and they both look good as new to me. Unlike the pH and ORP probes, I don't think the O2 probe is as sensitive to scratches but it should be kept from drying out by keeping it in solution when not sampling. And I think a gentle soft bristle brushing when calibration or reaction seems slow is effective in preventing scale build up.

Scott Roberts said:

Glen - how often do you need to change the membrane on your pinpoint meter?