DO850 Portable Dissolved Oxygen Meter Kit

4.65 12
  • Equipped with state-of-the-art Optical DO sensor: measures dissolved oxygen level in a RELIABLE and EFFORTLESS manner
  • Minimal maintenance required. Easy calibration
  • IP67 waterproof and dust-proof structure, ideal to be used in harsh environments
  • Comes with a complete test kit, including the meter, 10 ft optical probe, calibration cap, and a rugged carrying case
  • 3-Year warranty with the instrument, 2-year with the probe.
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  • State of the art Luminescent Optical DO Sensor

    • No Membrane, No Solution, No Hassle.
    • Quick & Accurate Measurements
    • The DO probe/tester/sensor does not consume oxygen. No limit on water flowing speed.
    • Maintenance-free. No need to calibrate before every use.
    • The service life of the luminescent cap is over 8000 hours. No need to replace the cap every year.
    • The special coating on the luminescent cap makes it anti-interference and unaffected by light and chemicals.
    • A calibration cap comes with the probe, which allows it to be calibrated and stored in saturated air.

    Intelligent Instrumentation

    • Auto Temperature Compensation; Auto Air Pressure (barometric) Compensation; Manual Salinity Compensation
    • Large backlit LCD screen, simultaneously displaying dissolved oxygen reading and temperature. Easy switch from mg/L and % to ppm and %.
    • Advanced digital processing technology, supporting stable reading and auto-lock display modes.
    • IP67 Waterproof dust-proof rating allows the meter to be used in harsh environments.
    • The foldable stand allows use as a benchtop meter.
    • Cable Length: 10 ft
    • Comes with a rugged carrying case, which includes a Dissolved Oxygen Meter, an optical DO probe, and the accessories.
    • Diameter of the probe cap: approximately 1.3 inches (3.3 cm)

    Dissolved Oxygen

    Dynamic Range

    (0-20.00) mg/L (ppm), (0-200.0)%


    0.01/0.1mg/L (ppm), 0.1/1%


    ±2% reading or ±2% saturation,

    whichever is greater

    ±2% reading or ±0.2 mg/L,

    whichever is greater

    Response Time

    ≤30 s (25℃ , 90% response)

    Calibration Points

    Saturation Point & Zero Oxygen

    Temperature Compensation

    Automatic, (0 to 50)℃

    Pressure Compensation

    Automatic, (60 to 120) kPa

    Salinity Compensation

    Manual, (0 to 45) ppt



    (0 to 50.0) ℃


    0.1 ℃


    ±0.5 ℃



    AA x 3 (1.5V×3)

    IP Rating


    Dimensions and Weight

    Meter: 88×170×33 mm/313g

    With case: 360×270×76 mm/1.3kg

    Product Certificate

    RoHs, CE


    Based On 12 reviews.

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    • 9/9/2021

      when u need accurate pH readings, this is the product...

      you can buy a pH digital tester for $15....
      they can get you close...
      but when you need ACCURATE, RELIABLE and CONSISTENT readings, this is top of the line pH meter.
      For any meter to be accurate, it must be calibrated. This kit comes with several calibration kits for different ranges of ph readings. IMO, this is the ONLY way to properly calibrate. Similar to a temp sensor... why calibrate it at -30F if you are reading temps at 250 deg. Same true here... you must calibrate by using a standard close to the pH you will be testing.
      The machine itself is large, robust, built to last. I compared these readings to some of my lower cost pH readers and this meter consistently read about 10-20% different. I have to trust this meter of course, as I had it finely calibrated. I test water pH to maintain specific levels, so knowing the proper ph is critical, so the product is ideal for my applications. For other applications, a lower cost pH meter will suffice, so you consider this when selecting a meter.
      Resolution .01, numbers easy to read, good contrast on display. Hard to find a flaw with this unit. Insructions are well written....

    • 9/9/2021

      Decent pH meter, not as good as the true lab grade brands

      This is a fine pH meter, just nowhere near as good as the meters commonly used in professional and academic labs. I am not sure this is worth their asking price. The reason I took off a star was for the high (in my opinon) retail price.
      This meter seems relatively precise (repeat readings were within a few hundredths of each other). I am not positive how accurate it is, as I don't have proper NIST traceable solutions to test with. I tested the included calibration solutions, as well as some extech single use calibration packets I had. The Extech solutions were technically expired, so I don't know which solution was more accurate. The readings for the two buffers disagreed by about 0.1 to 0.15. It is still relatively close. I do not have any reference solutions between the standard 3-point calibration values of 4, 7, and 10, so I couldn't test how well the calibration curve on this meter worked.
      Apera seems to market this meter as a lab grade meter, for a lower price. I don't know if I agree with that. I would classify this as a slightly more accurate consumer meter, for an increased price. True lab grade meters will have extra features this unit lacks, such as more calibration options (5-point curves, etc.), data logging/export, GMP compliance, etc. All the other lab grade meters I've used (Mettler, VWR, Thermo, etc.) feel much more robust than this meter does.
      There are some features that I do like. The included hard case is a nice touch. It fits everything nicely, and although the case isn't as robust as a Pelican case, it will protect the meter from mild abuse. I like that there is extra room inside the case -- I can store the batteries outside of the meter. I prefer to store batteries out of the meter if I am not going to use it for a while, just in case the batteries leak. I put the batteries in a plastic bag so it's easy cleanup if they leak -- the photos do not show this. I also appreciate that Apera put captive screws on the battery cover -- I always hate losing tiny battery compartment screws, and this will prevent that from happening. I do appreciate that Apera shipped the electrode with a proper 4M KCl solution to keep the electrode fresh. While I appreciate the inclusion of reference buffers, the seal on the buffer bottles was very difficult to open, and I would feel more comfortable with the buffers in a Nalgene bottle instead of this style of bottle that has a coated paper type sealing disk -- these tend to leak after a while.
      Overall, this meter works well enough, seems to be more accurate than the really cheap meters you can find on Amazon, but doesn't come close to the quality and features of a true lab grade meter. For the retail price here, I think you would be better served buying a lightly used/reconditioned lab grade meter. I am not really sure what market Apera is trying to target with this meter -- most of the people/industries that require very high accuracy and precision will usually have enough funds to get a proper lab meter; the home/recreational/hobbyist market will usually be served just fine by the cheaper pH meters or single-use strips.

    • 9/7/2021

      Rugged, Accurate and Complete with Case

      I do like this kit from Apera. I have been using one of their Pen Style kits for several years now and consider the brand very good in the measuring and instrumentation fields.
      The meter body is very robust and durable. It also is relatively light weight and is water resistant. The 4 buttons are easy to press and operate. The housing has a rubberized shell that doesn't slip in hand. It is easy to hold with one hand and use.
      The Auto Temperature Compensating probe is high quality and connects via a black RCA connector for Temp and a blue BNC connector for pH. The third cap to the left of those two is just a blank spot.
      The electrode is high quality and features a housing around the glass tip. It is one of their higher end probes.
      It is good for use in probe holders and makes an excellent bench top unit. The meter runs off of 3AAA batteries and so isn't made for continuous monitoring.
      I like the case as it holds all the essentials and protects everything in a lightweight yet sturdy and convenient to carry form factor.
      5 stars for quality at a good value.

    • 9/3/2021

      This Is A Good Quality Instrument- However Requires Considerable Calibration

      One obtained this to test drinking water. It is a good quality instrument, the directions are clear, but requires quite a bit of continuous calibration.
      This is good for professional level water testing.
      Due to almost continuous calibration gave 4-Stars.

    • 9/2/2021

      Good for hydroponics

      I grow vegetables in an indoor hydroponic garden and I bought this meter to closely monitor the pH of my solution. I tested it against controls and it is spot on. It is simple to use and a great addition to my hydroponics set-up.

    • 9/2/2021

      Awesome quality meter.

      The quality of this meter is well made. Tested the accuracy to all of my hanna and bluelabs meters. Calibration solution is provided. Comes in a nice hard case. Been using for mixing my hydroponics nutrients tank. Overall pleased with the quality of this meter.

    • 8/27/2021

      So Much Easier to Use than Traditional Testing Methods

      I had been wanting a Koi pond for years. My husband said they were too much work and one day I decided to have one put in thinking, how hard could it really be? They are just like big goldfish right? Yeah, no that's not really how it works and I kept killing off fish. Then I realized water had to be tested for different things (including oxygen and ph levels) and that testing the water wasn't nearly as easy as it should be in some cases. For ph you just dip a strip. For oxygen it was a whole darn process. This device makes it SO much easier. The readings are pretty accurate. Always very close to each other when taken minutes apart. For my needs it's fine but for someone who needs exact spot on measurements every time this could pose a problem. That's why I had to deduct one star. For simplicity of use and quality (it comes in a nice hard shell tool type case) it would definitely get five stars.

    • 8/26/2021

      High Quality

      This product is of high quality and accurate. Fast shipping!

    • 8/26/2021

      Easy of Use

      I was very pleased with the easy of setup and use of the meter. The accuracy has been very good.

    • 8/25/2021

      Solid so far.

      This was my first DO meter. I am a commercial fisherman and we like to pack the house as much as possible. This has really upped our game when it comes to loading the tanks and knowing if there's room for more or if we need to take some out. Reads fast, easy to adjust settings, we have our salinity set at 4 ppt and the readings seem very repeatable. I've seen the DO meters with the membrane and they seem fragile and alot like a hassle. This one fires right up, has a good backlight, reads good even in dirty water, and hasn't failed us in 4 months of hard use. I probably got 20-25 hours out of a set of batteries. Keep some spares handy. I would like to have a longer cord for testing oxygen and temp deeper in the water column.

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    The warranty period of the DO850 instrument (only the instrument) is 3 years from the date of purchase. That of DO803 optical DO probe (excluding sensor cap) is 2 years from the date of purchase. That of DO8032 sensor cap is 1 year from the date of purchase. If the above products or parts within the warranty period are not functional due to raw material defects or poor manufacturing, they are free for repair or replacement.

    This limited warranty does NOT cover any issues due to:

    • Accidental damage
    • Improper use
    • Normal wear and tear
    • Transportation
    • Storage
    • Failure to follow the product instructions
    • Unauthorized maintenance, modifications, combination or use with any products, materials, processes, systems or other matter
    • Unauthorized repair
    • External causes such as accidents, abuse, or other actions or events beyond our reasonable control.