Once a year, check that the prism surface is smooth and clean and free of erosion and small holes or digs. If the prism is scratched, eroded, or the gaskets seem to leak, contact service.
| CAUTION In 3‑A certified sensors, only authorized Vaisala service centers can perform prism gasket replacement and other repairs. If gaskets of 3‑A certified sensors are replaced in the field, the certification is no more valid. |