pH is the measurement of Hydrogen Ion concentration in an aqueous liquid, which determines whether a liquid is neutral, acid or alkali (base). pH is usually measured with a glass combination electrode which produces a millivolt potential proportional to the pH - this is them amplified inside the pH instrument to give an instantaneous value.
A portable pH meter is often used to corroborate a pH reading from a permanently installed instrument. A pH transmitter is an installed piece of equipment which converts the pH value to either a 0 - 20mA or a 4-20mA current signal for use with a PLC or chart recorder. Our pH controllers incorporate control relays as well as a (0) 4-20mA signal. Depending on which model of controller - these can be used to control a piece of control equipment such as a pump or solenoid valve. Often these pieces of control equipment can be controlled proportionally that is - causing the device to speed up, or dose faster / slower depending on the deviation from the desired set-point.
We refer to our glass bodied laboratory style pH sensors as pH electrodes, and our industrial bodied pH sensors as our pH probes. These are available with and without temperature compensation and with a wide range of connection types.