GEBRABIT Conductivity Module

OVERVIEW

GEBRABIT Conductivity module is An electrical conductivity meter (EC meter) that measures the electrical conductivity in a solution.

GEBRABIT Conductivity is capable of using 3V3 and 5V Supply Voltages that users can easily select with Considered onboard jumper select. This feature helps to use a wide range of microcontrollers for interfacing with this module.

Conductivity is the ability of a substance to carry the current. It is the reciprocal of resistivity. In liquid, we often use the reciprocal of resistance, and conductance, to measure the conductive capacity. The conductivity of water is an important indicator in measuring water quality. It can reflect the level of electrolytes present in the water. Depending on the concentration of the electrolyte, the conductivity of the aqueous solution is different.

In the International System of Units, the unit of conductivity is Siemens/meter (S/m), and the other units are S/m, mS/cm, and μS/cm. Conversion relationship is: 1S/m = 1000mS/m = 1000000μS/m = 10mS/cm = 10000μS/cm.         

This module uses the Definition of resistance:    ρ is the resistivity; L is the resistor element’s length; A is a resistor’s cross section. For the conductivity electrode, L is the spacing between two conductive sheets, and A is the area of ​​the conductive sheet. Definition of conductivity:  According to the above two equations, we can get this equation:  1/R is called conduction G.L/A is called vessel constant Q. The transfer function of the measurement circuit is:   R is the resistance of the electrode when inserted into an aqueous solution. In conclusion, we can get this equation:  Q is the vessel constant. It is constant and different from each electrode. In the schematic, R5 is 820Ω.|Vin| is also a constant depending on the signal generating circuit. Its value is about 200mV.

 As we can see, the conductivity is linear with the output voltage.

Key Features

• User-selectable module power supply voltage between 3V3 and 5V
• On Board, ON/OFF LED indicator
• GEBRABIT Pin Compatible with GEBRABUS
• GEBRABIT small package
• It can be used as a daughter board of GEBRABIT MCU Modules
• Featuring Castellated pad (Assembled as SMD Part)
• Separatable screw parts to reduce the size of the board

NOTE: The conductivity of a solution is highly temperature dependent, so it is important either to use a temperature compensated instrument or to calibrate the instrument at the same temperature as the solution being measured.