What are the parts of a soil pH meter?

3rd March 2020

	What are the parts of a soil pH meter?


	Shop for Soil pH Meters




			Probe
			The probe is the long thin part of the tool that comes into contact with the soil to test the pH levels. It has a pointed tip to easily penetrate the ground, when necessary. The probe contains the electrodes which measure the pH. It is possible to purchase extra-long probes which reach further into the ground, but as this is not the best method used for optimal results, it may be an unnecessary addition.

			A pH meter requires two electrodes in order to complete the circuit. In most of the basic soil pH meters, both of the electrodes are found in a single probe for extra convenience.

			Indicator
			The indicator is part of a plastic case, where all the electrical circuitry is also housed. The pH result is displayed on one of two types of indicator:

			Analogue pH indicators An analogue pH indicator has a needle which will move to point at the corresponding pH on the scale. The scale will not always run from 0-14. On some models, the extreme acidic and alkaline measurements will not be marked, as they are not likely to be detected. The scale usually runs from 3-10, and is viewed through a clear plastic cover. Analogue indicators do not require batteries.

			The colours on an analogue pH meter may also be simplified. As the scale often includes more of the acidic range, a large proportion may be red, leaving out the transitional orange and yellow colours. The scale does not go far into the alkaline measurements and green is often used to represent these numbers just above neutral.

			Digital pH indicators The digital pH indicator has an LCD screen, which will display the pH value, usually to one decimal place, but it is not colour-coded. Digital pH meters are generally capable of reading between 0 and 9. Digital indicators require batteries to power the screen.

			Extra features
			Hanging bracket There may be a small hanging bracket moulded into the plastic case, which can be used for storage purposes.

			Cable Generally, the probe is attached straight to the indicator box, but in some cases there is a cable in-between. This is beneficial because it allows you to move the indicator for reading rather than having to bend to see, but it also means the device requires two-handed use, which could be slightly inconvenient.

			Other functions It is possible to purchase soil pH meters which have combined capabilities for testing other soil aspects, including moisture, sunlight and temperature. These will look similar to the single-function tool but will have a second probe and a button to switch between functions.

			Analogue versions will have extra scales to read from whilst the digital ones will have an icon on the screen to distinguish the mode. These are similar in price and may prove more useful as they give a fuller understanding of your soil conditions.