A bimetallic actinograph has been developed by the Canadian Meteorological Division. It is proposed to equip a network of radiation stations with this instrument to supplement the existing network provided with Eppley pyrheliometers. Calibration agreement between the new actinograph and Eppley records for total daily radiation values is within ± 5%. This divergence includes errors of the Eppley and its recorder and scaling errors in both records as well as the strictly instrumental errors of the actinograph. The instrument therefore approaches the limit of practical accuracy for field use by non-technical personnel. Further development will be devoted mainly to increasing pen control (Span) and reducing cost and maintenance of the instrument.
* Published by permission of the Controller, Meteorological Division, Department of Transport, Canada.