YSI 100-4 [605378] pH / Ttemperature Electrode w/  4m Cable. The YSI 605378 100-4 is a pH and temperature sensor for the YSI pH100 meter and has Automatic Temperature Compensation (ATC) and a 1m (3.3') waterproof cable. A pH electrode is commonly attached to a pH meter to measure the pH of a substance such as water, food, beer, or wine in lab, industrial, and food applications. This electrode provides ATC with an internal thermometer sensor for accurate readings in fluctuating temperatures. The meter comes with a 4m (13') waterproof cable for immersion in liquids. An electrode, also called a sensor or probe, is an instrument used with a meter to test and measure parameters of a substance. All electrodes are probes or sensors, but not all probes are electrodes or sensors. Probes, such as temperature probes, are used to penetrate a material for measurement. Common electrode types are pH, total dissolved solid (TDS), and ion selective electrode (ISE). Electrodes can be half-cell or full-cell (also called combination) types. They can be refillable or non-refillable. Housing material is typically glass or epoxy, and sensors are commonly made with stainless steel or a glass bulb. pH electrodes, which measure the pH of a substance, often have a glass bulb. The bulb senses hydrogen ions, and generates a millivoltage that is picked up by the filling solution and transferred to a wire that connects to the pH meter. Ion selective electrodes (ISEs) respond selectively to ions in the presence of other ions. Electrodes are commonly used by researchers, manufacturers, and hobbyists in a wide variety of industries, such as aquaculture, agriculture, chemistry, food and beverage, wine-making and water-testing, and for scientific applications. An electrode can be used with a datalogger to assist in temperature measurement.