The 438 Series Multi-Wavelength Meter combines proven Michelson interferometer-based technology with fast Fourier transform analysis in order to measure the wavelength, power, and OSNR of as many as 1000 discrete optical signals. With features such as high accuracy, fast measurement rate, straightforward operation, and rugged design, the model 438 provides the most precise, reliable, and efficient WDM wavelength testing to satisfy the needs of any manufacturing engineer.