I want to purchase an accurate ph soil meter for home gardening and lawn...
I want to purchase an accurate ph soil meter for home gardening and lawn care. I have been looking at them online and thought it best to get a professional opinion before I buy. I am looking at the Gain Express ZD 06 model but am open to all recommendations you might have. Thank you.
Hi Lucas County, I am reluctant to suggest something to buy, but I have worked in a soil testing lab here in our county while I was going to college - a long time ago. The thing I learned at that time was that you had to make sure the solution you were calibrating the instrument with was also accurate. Most of the soil pH testers rely on a porous tip of sorts that must be kept moist at all times. A lot of the older models suggested to keep the tip inside the cup or holder with the solution up to the level so it would not dry out. Further keeping the instrument in the refrigerator was advised so it would be at a constant cool temperature and not fluctuate on hot or cold days out in the room.
OK, I did do some quick looking using google and "soil pH testers, edu" as the search line. I did come up with a paper by Washington State University on the use of the hand held devices. They suggested the "ExTech Soil ExStik 110" which I also googled and looked up for a price. It is listed as a little more than the Gain Express but it has the porous glass electrode and the reference liquid for accurate calibration. From reading the article, it won't do much good to purchase a tester without being able to make sure the calibration is accurate at the time you are using the meter. The kind with just the metal probe don't seem to worry about the testing/calibration liquid and I don't know if they can be calibrated properly.
Let's put it this way: If you were baking or cooking, you would want your thermometer for testing to be accurate. You can purchase a small thermometer that you can insert into the product. You can also test the thermometer by setting the probe into a glass of ice water. On the ones you can calibrate, there is a nut on the back side that you can turn and adjust the dial to make sure it is right. You would want the same thing in a pH meter. I would think that is why WSU endorsed that type of meter.
To sum up, get a meter that allows you to calibrate and/or adjust the setting to get the most accuracy from the meter. Read and follow all the directions on getting the most from the instrument. Store the meter where they suggest to keep the electrode working as long as possible. Don
Sorry I forgot the reference: http://pubs.cahnrs.wsu.edu/publications/pubs/fs205e/?p-page=2