| WARNING Do not remove the transmitter module CLT611 from its normal position without first switching off both the AC (mains) line and the battery power. |
| WARNING Do not look at the transmitter module CLT611 of the ceilometer from the beam direction when the transmitter is powered. |
| WARNING The transmitter replacement procedure is a service procedure and not maintenance. Contact Vaisala to replace the part. |
| WARNING Because of the danger of introducing additional hazards, do not install substitute parts or perform any unauthorized modification to the instrument. Return the instrument to a Vaisala office or authorized depot for service and repair to make sure that safety features are maintained. |