DO9100

Very good product, accurate and a very nice presentation. Great value for the price. Works as expected. Will be very helpful if you want to measure the oxygen levels in the water.

Throw away the instructions that come with this product. They are completely useless, and even misleading. There are several good you tube videos that show how to use this. Go by them instead. The readings I am seeing seem to make sense, but there is no way to gage the accuracy of this because there is no standard solution supplied to check it against. Would rather have a known standard solution to ensure the readings are actually correct.

Bought this to keep track of a personal pond. So far it has been excellent and extremely helpful.

This item might work well but the set up and use is very complicated. Plan to spend some time reading about how to use it properly.

I use it at my fish farm. Works great.

Company needs to spend a view bucks and get a truly bilingual university student in the USA to translate their instructions from whatever Asian language they were originally written in. If they are selling into the USA market the instructions should be English and Spanish, not whatever the near-English crap these instructions are, especially with a high technology device such as this. That having been said, if you are familiar with similar equipment and you noodle around with the alphabet soup of what they might be saying, you should be able to figure this out, but there is no help at all for negative or unexpected results, e.g., no troubleshooting at any level. Is this thing broken or did I just do something out of order? No way to know. As a customer, it is not my responsibility to put up with this silly nonsense and fumble around with it until I work it out. It is the responsibility of the manufacturer/vender to supply clear and readable instructions in the language of the marketplace they are selling into. If they are unwilling or unable to do so, they should remove themselves from the market. This is especially true of online sales where I cannot ask a local salesperson to show me how it works. Adding onto original review. You must calibrate this with anaerobic water, which is not supplied, nor is there any information on how to obtain any. It has two expendable parts, the electrode flute and the electrode membrane. A small amount of each come with the unit with absolutely ni information on how to obtain more. I guess you throw it away when you use the last of it. I am truly amazed at the immature marketing abilities of this company, buying expendables can keep a customer returning for years, they have sliced their own throats here, but maybe not, maybe it just doesn’t last any longer than the initial replacements. The gift just keeps on giving. I now have anaerobic water so I can do two step calibrations as specified, I do the calibrations before each use as specified (which is a royal pain when checking multiple tanks), and the first reading taken is within an acceptable and expected range, but it goes downhill from there. Each reading after that becomes more and more wildly variable despite resetting and recalibrating, until it is giving readings beyond the ability to contain oxygen without bubbling it off (all readings taken at STP or very close to it), causing me to question any reading I am getting from this. Overall, this is intolerable product quality and operation. Another slow and careful round of testing just to be sure I’m not doing something wrong, and this is going into the returns bin.

Easy to use and fast data Aquisition

I purchased this DO meter to monitor my pond. The unit had to be calibrated every time I used it and I had a lot of inconsistency with calibration. I never really knew if I was getting good readings and at times it read so low that I should have seen distressed fish but that was not the case. Finally, after about a year, the unit would no longer calibrate. I will not purchase another from this manufacturer.