Apera Instruments SX751 pH/ORP/DO/Conductivity/TDS/Salinity/Resistivity/Portable Handheld Multiparameter Meter Kit, Silver

Great quality for the price.

Got this DO meter for my pond. Had no experience with DO testing. The video tutorial is really helpful! Finding a proper swirling speed in water is critical to getting a stable reading. Thumbs up for the elegant DO probe design!

I cannot understand the instructions! They assume too much! I called tech support and cannot understand a word the girl is saying! She had to pull out the instructions and read them! Quite obvious the first time she has read them or dealt with the meter! I asked 5 times to be transferred to someone that knows how to operate the meter! I finally hung up! The meter appears to be high quality and I don’t doubt it works but good luck trying to figure it out with the instructions that come with it! I’m dissatisfied completely

This dissolved oxygen meter is durable, easy to calibrate, easy to use, and gives accurate and consistent readings. It is equally at home in the lab and the field. The handy hard-shell case with secure slots for the equipment makes transport, even in rugged conditions, secure and safe. Setting up from the case and breaking it down to return to the case takes around a minute and is simple enough for students or assistants to do reliably.The directions provide a nice, easily comprehended overview of instrument operations. Online resources offer more in-depth advice and instructions for those less familiar with dissolved oxygen testing or even laboratory equipment in general. Even if this is the first piece of scientific laboratory equipment you have touched, do not be intimidated. It is tough, almost foolproof in its operation, and intuitive. Even amateurs in dissolved oxygen measuring will be up and running reliably in no time. There are no instrument-specific idiosyncracies to deal with, and this dissolved oxygen meter operates similarly to other dissolved oxygen meters.Automatic calibration for temperature and salinity are important features for an instrument intended for field use. These calibrations seem accurate, and the automatic part means no hassle for the operator. No nomograms or charts are needed to calibrate and correct for temperature and salinity differences since these are built into the automatic functions. These features are convenient in areas with a significant difference in the salinity or temperature of waters near each other. Barometric pressure correction is an easy entry using the data entry mode on the screen. This data is readily available from aviation weather, cell phone weather apps, and many wristwatches. Once the pressure data is entered, it is good for a reasonable period in a location. It does not usually need re-entering frequently.The membrane is well protected in the design of the probe and lasts for quite a while. You would almost have to go out of your way to damage it. In either event, three spares come with the unit. The calibration chamber doubles as a protective sleeve for the probe and is a nice feature. The probe and cord are certainly waterproof. I did not test to see if the whole instrument was, but simple weather and water spray do not seem to affect it.Retesting the same sample yields similar results. The difference was 0.03 mg/L or less in the samples I tested. Results, in general, were accurate, and where I had known samples of water to test, the results were accurate to within 0.05 mg/L. These results are as good as most oxygen meters can obtain.Overall this is an economical, reliable, easy-to-use and maintain dissolved oxygen meter that does its job well and has good durability. I am impressed with it.

Meter came in a big box with empty slots left and right feels empty. Wonder what’s in the empty slots. First use took 1 min for meter to stable. Easy to use as all apera. Calibration is easy. Meter feels heavy for the size. If only the box can fit meter back in without removing the cable again.. 4 stars cuz I don’t know how long it will last yet.. over all not bad.

My wife is, essentially, a freelance science teacher. Schools hire her to develop their science programs or augment their science staff when they need a little more scientific rigor. So I figured he would be a great person to evaluate this water testing kit. Here’s what she told me.- They can’t count. This test set actually does eight water quality parameter tests: Acidity (pH), Oxidation-Reduction Potential (ORP), Dissolved Oxygen (DO), conductivity, Total Dissolved Solids (TDS), salinity, resistivity, and temperature.- There are 21 routine water quality tests but this covers almost all the standard water quality tests. Of the standard water quality tests, the only one this doesn’t cover is turbidity.- This set compares very favorably with a similar set sold by a competitor that retails for nearly $3000. Unfortunately, she didn’t have access to that other test kit at the moment so we weren’t able to do a head-to-head test to determine each set’s relative accuracy.One area where this might help that I hadn’t considered was home brewers - beer makers - who need to understand water quality when they’re brewing. According to a beer brewing website I read, the important tests are Water Hardness, Alkalinity, pH, Salinity, TDS, Conductivity, DO, and Potassium. So this meter can definitely help brewers make better beer.I know, it may seem like a lot of money for a brewer to test their water. But a few of the brewers I know are serious - I mean REALLY SERIOUS - about the quality of their beer. This seems like an easy way to step up your game.

Not just for labs, but also great for households. This is a great test instrument to buy because of the usefulness of pH, ORP, Conductivity, TDS, Salinity, Resistivity if you have any hobbies or DIY projects related to fish aquariums or reverse osmosis water.The display is a bit smaller than their dedicated pH/temperature kit, and that's the main difference. Otherwise this is just so much more useful when you can get the TDS of reverse osmosis water, salinity of a marine reef aquarium, etc. rather than having to use totally separate instrument kits for precision measurements.First thing out of the box I use the 3 pH calibration fluids to calibrate the pH probe. That took about 5 minutes. (You will need some RO or distilled water to rinse the probe in between.) Then dip the probe into the fluid being measured and it shows a happy face icon when the reading is stable enough to be considered a measurement.Conductivity readings are even more straightforward.It's simple, it's precise, and the kit has just the right combo to be useful for many projects.