Using pyroelectric sensor in conjunction with 18 Hz chopper, Model RM9 measures wide range of radiation, from UV to deep IR. Digitally synthesized lock-in amplifier minimizes external noise, allowing sensor to measure power levels as low as 100 nW or less. To display measurements, Model RM9 can connect directly to any standard meter or PC interface. Unlike other radiometers, RM9 is calibrated over entire range of wavelengths, from 0.15–12 µm, not just single wavelength.