THE ARTIFICIAL SEASONING OF TIMBER 4" 



instrument can be corrected from time. to time to agree with the wet and 

 dry bulb thermometers. 



With an Erith or other progressive dryer, the recorder bulbs are 

 placed in the dryer near the hot end. The records should show either 

 two concentric circles in the case of a dial instrument, or two parallel 

 hnes with the drum type. 



There are, of course, unavoidable fluctuations due to opening of doors 



60TM THERMOMITERS 

 READING EQUAL 



DRY 



BOTH PENS DM 

 SAME LIME 



OBY Bum 



W£T BULB 



BULB ® ® BULB 



THERMOMETERS READIMG EQUAL, OR RECORDER PEMS TOCETMEB 

 INDICATES WET AIR IM KILM 



BIG DIFFEBEMCE 

 BETWEEN TWO 

 THERMOMETERS 



DAY 

 BULB 



(J>) 



PENS WIDE. APART 



DRV BULB 



wtr 



BULB 



BIG DIFFEREMCE BETWEEN THERMOMETERS OR RECORDER PEtJS 

 INDICATES DRY AIR IN KILN 



and the Uke, but for good working the wet and dry bulb readings shotild 

 be practically steady. 



With compartment dryers, where the temperature and humidity are 

 varied according to a predetermined course, the temperature Une wiU 

 rise gradually from atmospheric temperature to full heat, and the wet 

 bulb line will start close to the temperature line (indicating great moisture), 

 and gradually fall away from it as drier air is used. 



The above diagrams show the analogy between the wet and dry bulb 

 thermometers, and the recorder, under extremes of wetness and dryness. 



