GISNPA Dissolved Oxygen Meter with ATC, 0-40.00 mg/L Measurement Range, DO Meter with Electrode Filling Fluid and Anaerobic Water Calibration Powder

El producto llego un día antes de lo esperado, que fue excelente porque ya lo necesitabamos. El equipo funciona bien y es fácil de manejar.

I have a passion for aquatic plants and hydroponics so the precision of my water's oxygen levels is crucial, and this oxygen meter has become my trusted companion. With a measurement range of 0-40.00 mg/L, this meter provides the accuracy and reliability I need to ensure my aquatic garden thrives. The automatic temperature compensation (ATC) feature is a godsend, adjusting for different water temperatures and giving me peace of mind that I'm always getting the correct readings. It's user-friendly, too—calibration is straightforward, and the readings are easy to interpret. This dissolved oxygen meter has elevated my gardening game, leading to healthier, more vibrant plants. It's a five-star tool that any serious aquatic gardener should have in their arsenal!

I got this to check the water in my nearby Lake and also the water I been producing in my home distiller (before and after distillation). Difficult to follow instructions but much help thanks to another reviewer. They provide a small amount of sodium sulphite powder to absorb residual oxygen to make a known blank. But fortunately sodium sulfite is cheap and easily available; don't bother trying to make your own by burning sulfur to get sulfur dioxide because you get some sulfur trioxide (becomes sulfuric acid) as a byproduct.Depending upon your need for dissolved oxygen measuring range available and exactness (accuracy) and repeatability (precision) you may need more than this starting type system but for cost this is entirely reasonable; the higher-level instruments cost many thousands of dollars.In conclusion: recommend. This may be all you need for your application(s) or help you understand some of the problems of measuring and help decide if you need more.

OK, as many people says, the manual is somewhat incomplete with errors. But assembling the tool can be accomplished with this manual. 100% calibration is easy. 0% calibration is confusing as the manual says to use 30mL distilled water but the packet has big "250-mL" sticker. It's up to you if you want to use 30-mL or 250-mL but since the purpose of using it is to deplete oxygen in the solution, I would use 30-mL.Once I dip the probe in the water I want to measure DO, the reading will continue to go down almost endlessly (gradually slows down). There is no explanation on how to measure DO in the manual. Am I supposed to use the reading when the number is somewhat stable? Or do I have to wait until it completely stops? How much water/solution am I supposed to use for measurement? Those I guess I have to figure out myself.Other thing I noticed was 6 membranes that came in the package was bit dirty and also has wrinkles. I am not sure how much this will affect the reading. I have washed them with distill water and air-dried. I think wiping with paper towel etc. will scratch the membrane and cause erroneous readings.Anyway, assuming I am using it correctly, measuring DO was easy. The first recorded numbers seemed reasonable. I will continue to use it and see!+++After 1 week of use, I found the temperature is off all the time. I used two other thermometers and found this one to be about -0.2 to -4.8 degrees off. I don't know how the thermometer works on this tool and I don't think there is a way to calibrate it... As the temperature affects the DO reading, regret to say I think this device is unreliable. I'm still using it just to see ups & downs of DO.

These instructions are obviously translated very badly from another language. I am still struggling to figure out how to calibrate with the anoxic solution to zero.