Waters TA Instruments Photocalorimeter Accessory (PCA) is designed for use with the Discovery DSC, Discovery DSC 2500, and DSC 250 modules in differential photocalorimetry studies of UV curable materials. It includes a 320–500 nm internal filter. An external filter adaptor (P/N: 935014.901) and external filters are available to provide narrower wavelength ranges. A 200W high-pressure mercury lamp delivers light and transmits it to the DSC cell using an extended range dual quartz light guide cable, providing a maximum intensity of 500 mW/cm². The DSC/PCA system operates from ambient to 250°C as supplied, from -50°C to 250°C with the optional RCS90 cooling accessory, and from -40°C to 250°C with the optional RCS40 cooling accessory. Shutter and exposure time control are managed via Waters TA Instruments Advantage software (V4.9.2 and higher) supplied with the DSC module or TRIOS software supplied with the Discovery DSC.