What is a portable digital conductivity meter? Portable digital conductivity meter is a commonly used detection instrument, suitable for on-site measurement of liquid conductivity, with advantages such as stable performance, flexible use, and high reliability. Today we will mainly introduce the measurement principle and characteristics of portable digital conductivity meters, hoping to help users better apply their products.
The principle of portable digital conductivity meter measurement
Conductivity is the ability of a solution to conduct electrical current expressed numerically. The conductivity of water is related to the amount of inorganic acids, bases, and salts it contains. When their concentrations are low, the conductivity increases with increasing concentration. Therefore, this indicator is commonly used to estimate the total concentration or salt content of ions in water. Conductivity (G) is the reciprocal of resistance (R). Therefore, when two electrodes (usually platinum black electrodes) are inserted into a solution, the resistance R between the two electrodes can be measured. According to Ohm's law, at a constant temperature, this resistance value is proportional to the electrode spacing L (cm) and inversely proportional to the electrode cross-sectional area A (cm2), that is, R=ρ × (L/A), where ρ is the resistivity, which is the resistance of a conductor with a length of 1cm and a cross-sectional area of 1cm2, and its magnitude depends on the nature of the substance. According to the above formula, the conductivity (G) of a conductor can be expressed as follows: G=1/R=(1/ρ) × (A/L)=K × (1/J), where K=1/ρ is the conductivity and J=L/A is the electrode constant. The conductivity of an electrolyte solution refers to the conductivity of two parallel electrodes that are 1cm apart when filled with 1cm3 of solution. As can be seen from the above equation, when the electrode constant (J) is known and the solution resistance (R) or conductivity (G) is measured, the conductivity can be obtained.
Characteristics of portable digital conductivity meter
One click button automatic calibration:
The instrument can be automatically calibrated at one point per range with standard conductivity solution. During calibration, the instrument automatically recognizes the calibration solution. If you use the wrong or significantly deviated conductivity solution for calibration, the instrument will automatically sound an alarm.
Automatic range conversion:
When measuring conductivity or total dissolved solids (TDS), the instrument has an automatic range conversion function. After the electrode sensor is immersed in the solution, the BEC portable model will automatically scan the current measurement value and convert the range, and the instrument will display the endpoint measurement value with a resolution of.
Temperature coefficient can be set:
Solutions containing different ions often have different temperature coefficients, and accurately setting the temperature coefficient is crucial for measurement. The BEC portable model can be set within the range of 0 to 3.9% per degree Celsius.
Can set electrode constant:
When measuring high or low conductivity solutions, you need to choose conductivity electrodes with different constants. The BEC portable model has three electrode constants to choose from, and you can set them according to the selected electrode. The instrument will automatically convert the endpoint measurement value.