Extech DO600 Waterproof ExStik II Dissolved Oxygen Meter

Using it to monitor aquarium O2 levels day and night at different depths to ensure stocking density doesn't cause depletion levels. Very accurate based on calibration.Had an issue understanding the calibration process at first and technical support was easy to access and walked me through the process. I appreciate that. Might buy other products from them.

Great kit and it works just fine. Took it out for a week to monitor various DO levels in streams. Had no issues and it was really accurate for the work we were doing. One thing users need to realize is that it needs to be calibrated each week or sooner at a minimum (manual states so). If you plan to be away from the office or in a remote area for some time, bring most of the kit with you so you can recalibrate it several times. Otherwise your samples are likely to be inaccurate.

Have tried to use it dozens of times and have given up. I changed the tip, calibrated it, got a new one, because the first one froze up and it never worked right. I could not trust any readings, they were usually so out of the ballpark that there was no doubt it was not working.

It is nice to not have to deal with a meter box to lug around. I use this for measuring water quality of fish tank/aquaponics parameters. This handheld gives the temperature rapidly. The dissolved oxygen reading takes about 20 to 30 seconds to stabilize. The calibration and adjustability makes this a very convenient tool to have in one's pocket or hanging from the neck.

We've used this in the field for some 18 months. It's quick, responsive and nicely made. It's accurate, sold at a good price and a 5-star product.

We use a number of meters on the fish farm on a daily basis, rain or shine, hot or cold. I bought this meter as an emergency backup to use when one of the other meters went down, to send with the truck, or to loan to a customer. The price was low enough to be able to afford to lose it and not worry about it.Observations: the temperature reading is about two degrees C low. Every time you shut off the meter you lose your altitude setting, so you have to re-enter the altitude correction every time you turn it on. The meter is very slow to come to a reading. The probe floats, and it is difficult to position where you want it. The probe gives very unstable readings; unless you put it in a steady flow of water, you are guessing. The meter does not deal well with super saturated readings, at all.I once took the probe out from a warm, humid building into the cold outside, and enough moisture had already penetrated the meter the buttons froze up. If you use this meter, keep it out of rain or humid environments. It is in no way, shape or form water resistant.Overall, if you have nothing now, this is better than nothing. If you need accuracy, consistency and durability, this will not make you happy. There are much better choices just a few dollars higher.

Purchased in October 2016. Easy to use. In addition to disolved oxygen displays temp. However very slow working. In January 2017 stopped working all together. It goes through self calibration then displays 00.00 for both DO and T. When was operational it was OK.

Works great

Great product and great support

Für den Preis darf man sicherlich nicht viel erwarten, aber zumindest eine verständlich Bedienungsanleitung wäre cool gewesen.

My use for the unit is somewhat unconventional, as I use it to measure O2 content in very small volumes -- 250 microliters or so. I use this to measure oxygen decay carried out by an oxygen scavenging enzyme. Given that this instrument costs 10x less than a dedicated 'scientific grade' one, I am quite happy with it. I mount the probe upside down, and deposit 250 ul into the 'cup', which gives me a bit of a meniscus. I control the temperature of the probe by wrapping a kapton resistive heater around the tip, and attaching a small thermistor to it.The response time of the unit is about 30 sec. Upon adding a freshly prepared oxygen-scavenging enzyme solutoin to the tip (now used as a 'cup'), the measurements drop from about 7.0 mg/L to about 0.2 mg/L in 2-3 minutes, which seems the lowest the instrument can estimate. If one immediately seals the tip with an oxygen-inpermeable film, the readings stay at 0.1-0.2 mg/L for at least 2 hrs. Once one removes the seal, the readings go back to 5-7 in 5-10 min, consistent with the diffusion rate of oxygen. My measruements are probably slower, b.c. the volume inside the probe is comparable to the volume in the cup.My only complaint is that the built-in temperature probe is mounted far away from the tip, and does not reflect the temperature of the tip. So, when I measure the temperature of the tip at 42C, the built-in probe shows 28C or so. So one needs to use a separate probe if one after small volumes like I am.

Ideal for Rivers Trust Organisations to find out what are the oxygen levels in slow overgrown watercourses resulting fromm poor EA maintenance and abrogation of statutory duty.. In Durable case

read anything... badly! lol You can add 1, 2 or 3 air pump in the same bucket, always the same reading. You take a measurement of tap water, back to the original and have a different reading...I guess the more accurate one worth it even if they are costly.