5 Things You Need to Know About Electrochemical Sensors
If you want to do a good job, you need the right equipment. Sounds like common sense but even with the right equipment, you won’t be effective if you don’t know how to get the best out of it.
Whether your work in a hospital, in the pharmaceutical industry or are part of the fast-growing army of engineers, you no doubt work with plenty of high-tech equipment. It goes without saying that work safety is of utmost importance, not just for yourself but for those you serve and a key component of job safety is getting to know the equipment you need to be effective.
One class of apparatus you need to know about electrochemical electrodes and sensors. There are plenty of ways to use them – and things to know before you fire them up.
Let’s get to know electrochemical electrodes and sensors a little better with these five important facts.
1. What Does An Electrochemical Electrode/Sensor Look Like?
More likely than not, you’ll come across a glass pH sensor (also referred to as a pH electrode or pH probe) as these are the most common but there are other types to measure different parameters. Don’t be deceived by its humble design; there’s a lot going on inside that tube. When looking at it, you’ll see a glass tube with a little bulb at one end and an electrical wire or connection at the other. The tube may be a single tube (measurement electrode only) or may be a tube in a tube (combination sensor with both measurement and reference electrodes). The inside of the tube(s) is filled with an electrolyte, usually a buffered chloride solution. The pH of the solution inside is usually neutral (pH~=7) but can vary depending upon the measurement application.
That tube with the bulb at the end of it is the measurement electrode and has a length of silver wire coated in silver chloride that runs down the length of the tube to the bulb. The outer tube (or a separate sensor altogether) contains a reference electrode similar in makeup to the measurement electrode with the key difference that it is electrically connected to solution being measured. Here’s the important thing – the bulb at the end is thin and made of a special pH sensitive glass. It’s this that allows the sensor to take a measurement.
2. How Does It Work?
pH sensors measure pH by measuring the voltage or potential difference of the solution in which it is immersed. Here’s what’s going on in that little glass tube: if your solution is acidic, the concentration of hydrogen ions in it will be higher that the concentration of hydrogen ions in the sensor buffer solution and the sensor will see a positive potential difference in the measured solution when compared to the measurement. Alkaline solutions are the opposite. There are fewer hydrogen ions in an alkali solution and therefore a negative potential difference. The greater the difference of hydrogen ions in either direction, the greater the potential difference.
3. Calibrate Your Electrochemical Sensor
Before you even get started, make sure your electrode sensor is calibrated. Don’t know how to do it? It’s pretty easy. Round up a few buffer solutions of known pH. Dip your pH sensor into them and calibrate accordingly. It’s really that simple. Again, knowing your equipment inside and out is important. Don’t start your work with a sensor that’s off.
4. How to Clean Your Sensor
Your sensor is a sensitive piece of equipment. It’s essential to measurement performance and workplace safety to keep it properly calibrated and cleaned. Never vigorously wipe your sensor with a cloth; it’s far too delicate. Instead, start by gently swirling it in a cleaning solution and rinsing it with deionized water. Depending on what you used it for, there will be different solutions for cleaning. Take care of your sensor and treat it gently.
5. Who Needs an Electrochemical Sensor?
Electrochemical sensors are found in a myriad of jobs and applications. Doctors, engineers, water treatment facilities, food industries, and pharmaceuticals are just a few examples of where sensors can be found. Make sure you use the best ones to get the best readings.
Call South Fork Instruments today for more information or questions about Electrochemical Sensors.