If you work in the biopharmaceutical industry, you’re likely familiar with the concept of light and color measurement and the equipment used in these processes — radiometers, spectrometers, spectroradiometers and spectrophotometers. While all four instruments are used to detect light and energy, they vary widely in their capabilities, applications and intended purposes. It’s important to know and understand the differences between these instruments to determine which one will adequately serve your needs.
What Is a Radiometer?
A radiometer measures the electromagnetic energy present in a wavelength range. This instrument is typically used to detect and quantify energy outside the visible light spectrum and measure infrared and ultraviolet light. The radiometer begins by measuring the incoming current or voltage, then corrects the signal to create a calibrated light level measurement. With this information, the meter provides one reading for all wavelengths of light that reach the sensor.
Pros and Cons of Radiometers
Radiometers are inexpensive and portable, making them a cost-effective and practical choice. This instrument can eliminate troublesome UV energy and detect and measure heat energy on surfaces. It also has one sensor that allows it to quickly measure intended wavelengths. However, radiometers cannot identify emitted wavelengths or their individual amplitude.
What Is a Spectrometer?
Spectrometers detect and measure wavelengths using numerous sensors and an optical grating or prism to break down the energy into components. Like a camera, spectrometers take a snapshot of the light and create an image depicting the output. They let in the light, break down the signal and spread it across a sensor range. This sensor separates the wavelengths and scales it based on incoming signal amplitude and sensor sensitivity.
