Profile: Hellma UK Ltd. specializes in producing fiber-optic probes. The standard immersion probes are ideally suited for laboratory measurements. As with conventional cell measurements, the collimated light beam passes through the solution only once. The measuring head is made of SUPRASIL® 300 quartz, and secured into the stainless steel top section with a FFKM-O-Ring. The removable metal sleeve protects the immersion probe from damage, and reduces the amount of incoming ambient light.