Scientists are always greatly concerned with the accuracy of their testing. This is the case whether they are measuring the concentration of a solution, the nature of DNA, or the weight of a sample.
To produce trustworthy conclusions based on your tests, it is extremely important for you to understand accuracy. In this blog article, we will delve deeper into the concept of accuracy, and look at what can be done to improve accuracy in the lab.
Accuracy explained
When making measurements we always aim to get the true value of whatever we are measuring. The extent to which we achieve this is referred to as accuracy. Accuracy is often mistaken for precision but the two concepts aren’t quite the same. Precision is the extent to which the measurements you record are similar to each other.
If you are looking to learn more about how accuracy compares to the concept of readability, error and uncertainty, you can read our article entitled “What is Weighing Uncertainty?”.
Why is it Important to be Aware of the Accuracy of Measurements?
Accurate measurements are crucial in lab tests. Even small errors in measurements can cast doubt on the validity of your entire test. This can waste time and money invested in the test. Additionally, tests often involve multiple scientists, so it’s important to ensure that errors are minimized to avoid any potential discrepancies or inconsistencies when trying to reproduce test results.
Can a Measurement Ever be Truly Accurate?
In reality, a measurement can never be truly accurate. With every measurement, there will always be factors outside of our control that will introduce a range of uncertainty, or margin of error. However, there are still protocols we can put in place to help improve accuracy.
How to Improve Accuracy in the Lab
Ensure your instruments are properly calibrated
We purposely put this step at the top of the list because of how important it is when it comes to ensuring the accuracy of lab results. The process of calibration involves correlating the readings of an instrument with a certain standard in order to ensure the instrument is the most accurate it can be.
Instruments tend to vary greatly in terms of complexity, but usually have user manuals that have recalibration recommendations. General routine checks (other than calibration) should also be done on equipment. These routine checks might also differ vastly depending on the instrument in question. Once again, the user guides for lab equipment will be helpful with this.
Choose the right equipment
In a scientific lab it’s crucial to select the correct instrument for your test. For instance, when you need to measure a precise volume of liquid. Choose a graduated cylinder if it’s a relatively small volume like 10 millilitres, but if you’re working with a larger volume like 500 millilitres, opt for a beaker. Using the right instrument for the job ensures accurate measurements in your test.
Correctly record significant figures
How many significant figures (sometimes referred to as “sig figs”) you use and record while conducting lab tests is important. Significant figures are the number of digits in a value, with the first non-zero digit of a value the first to be counted as a significant figure.
Record multiple measurements
Taking an average of multiple measurements for attributes of the sample that you are measuring may help increase how accurate your measurements are. You may face the challenge of not being able to repeat lab tests (as some samples are more difficult to measure repeatedly than others). In the case that you are carrying out a lab test where one sample can not be remeasured multiple times, you can just repeat your test to deduce new measurements.
Account for individual technique
Scientists may differ in the way they carry out tests, and this can affect the results that they produce in a lab. One scientist might record a measurement in the lab that is different from another’s simply because of the technique they use. To reduce this issue you could aim to document the most recent procedure that was used to record a measurement.
By making this documentation as clear and as descriptive as possible it would help the lab personnel who came in to record a measurement to conduct the process in the same way as the lab personnel previously. It may also help to make sure lab personnel are assigned to make specific measurements instead of repeatedly changing personnel. Ensuring lab personnel are properly trained to carry out specific tasks (especially if the task is one that requires a lot of manual input) will also help improve accuracy in lab testing.
Conduct a Measurement Systems Analysis (MSA)
When it comes to ensuring the accuracy of data used for analysis, Measurement Systems Analysis (MSA) is crucial. This thorough assessment involves identifying the components of variation in a process to evaluate the test method, measuring instruments, and the entire method of obtaining measurements. MSA helps to prevent the production of incorrect results, and allows researchers to understand the implications of measurement error for decisions made about a product or process. MSA is particularly important in the lab to ensure consistent and usable final results.
In order to achieve better accuracy in lab tests, it’s important to take necessary precautions. Although complete accuracy may not be possible, at Techmate we prioritise the importance of lab test accuracy and provide a variety of equipment such as thermometers, pH meters, and pipettes to ensure the most accurate measurements. Feel free to contact us if you require assistance in selecting the appropriate lab equipment. We would love to give you a helping hand!
