V 3.0 Revised 7/2/18 pH Probe Silver / silver chloride Reads pH Range 0 − 14 Resolution Response time Max pressure Max depth Temperature range °C Cable length Internal temperature sensor Time before recalibration Life expectancy Maintenance +/- 0.0001 95% in 1s 100 PSI 60m (197 ft) 1 − 99 °C 1 meter No ~1 Year ~2.
Specifications Max depth Cable length Weight Speed of response Isopotential point Dimensions BNC connector Sterilization Cable Length 1m (3.2’) 60m (197 ft) 1 meter 49 grams 95% in 1 second pH 7.00 (0 mV) 12mm x 150mm (0.5" x 6") Yes Chemical only 30mm (1.
Operating principle A pH (potential of Hydrogen) probe measures the hydrogen ion activity in a liquid. At the tip of a pH probe is a glass membrane. This glass membrane permits hydrogen ions from the liquid being measured to defuse into the outer layer of the glass, while larger ions remain in the solution. The difference in the concentration of hydrogen ions (outside the probe vs. inside the probe) creates a VERY small current.
A pH electrode is a passive device that detects a current generated from hydrogen ion activity. This current (which can be positive or negative) is very weak and cannot be detected with a multimeter, or an analog to digital converter. This weak electrical signal can easily be disrupted and care should be taken to only use proper connectors and cables.
NEVER EXTEND THE CABLE WITH CHEAP JUMPER WIRES! A 1 5 10 15 20 A B B C C D D E E F F G G H H I I J J 1 5 15 15 20 DO NOT CUT THE PROBE CABLE WITHOUT REFERING TO THIS DOCUMENT! 5 Copyright © Atlas Scientific LLC
DO NOT MAKE YOUR OWN UNSHIELDED CABLES! A 1 5 10 15 20 A B B C C D D E E F F G G H H I I J J 1 5 15 15 20 ONLY USE SHIELDED CABLES.
Extending the probe cable length You can extend the cable to greater than 100 meters with no loss of signal. Atlas Scientific has tested up to 300 meters without a problem, however you run the risk of turning your pH probe into an antennae, picking up noise along the length of your cable. If you want to extend your cable, we recommend that you use proper isolation, such as the Basic EZO TM Inline Voltage Isolator, or Tentacle Shield. Be sure to calibrate your probe with the extended cable.
Helpful operating tips pH probes must stay wet and cannot be allowed to dry out, this is why every pH probe is shipped in a plastic soaker bottle containing pH probe storage solution. The probe should remain in the bottle until it is used. If the probe is used infrequently, the bottle and its solution should be saved and the probe stored inside. 1 Take out the probe by loosening the cap of the soaker bottle by turning it counter clockwise, and pulling the probe out.
3 Vigorously stir the probe in the sample, calibration solution, or rinse solution. This action will bring solution to the probes surface quicker and improve the speed of response. Response time Probe cleaning Coating of the pH bulb can lead to erroneous readings including shortened span (slope). The type of coating will determine the cleaning technique. Soft coatings can be removed by vigorous stirring or by the use of a squirt bottle. Organic chemical, or hard coatings, should be chemically removed.
How often do you need to recalibrate a pH probe? Because every use case is different, there is no set schedule for recalibration. If you are using your probe in a fish tank, a hydroponic system or any environment that has generally weak levels of acids and bases you will only need to recalibrate your probe once per year for the first two years. After that every ~six months.
