is recorded on a chart, when the level of the water rises. To provide a record over a longer period, these instruments are equipped with a device for emptying the float chamber once it becomes full. This is usually a siphoning process which should take no longer than 15 sec. and should start and end abruptly to minimise errors, as rain is not recorded during this process.
16 - In the tipping bucket type, the rain is led from the receiving collector to alight metal container divided into two compartments. This container or bucket is so balanced that when one compartment holds a predetermined weight of water, it tilts allowing the compartment to empty and the rain to fall into the other compartment. The tilting of the bucket is used to operate mechanically either a counter orb brecording device, or an electrical switch which allows for
