EVAroratED M1iK—S?TeERILIZING 139 
It is advisable and important to establish the efficiency of 
heat distribution in the sterilizer by accurate test. For this 
purpose the use of cans equipped with automatic thermometers, 
similar to medical thermometers, but registering sterilizing tem- 
peratures, may be found practical. Such cans are placed in 
different parts in the cages of the sterilizer at the time the ster- 
ilizer is loaded, and at the conclusion of the process these 
©) () 
Can fitted with Closed Top 
and Tell-Tale Thermometer 
for Open Bath and Retort 
ee 
Fig. 62. 
Fig. 60. 
Wrench for sealing and 
Evaporated milk can opening can 
with tell-tale ther- 
mometer, complete 
Pig. 61. 
Tell-tale thermometer 
Courtesy of Taylor Instrument Co. 
thermometers indicate the maximum temperature to which the 
contents of the respective cans were heated. Uniortunately 
these thermometers are not always accurate and often they do not 
function properly. ‘Then again the jars to which they are sub- 
jected in the revolving cage and again when the trays contain- 
ing these cans are removed from the sterilizer, frequently change 
the position of the mercury column, rendering its readings un- 
reliable and misleading. 
Another and very simple and reliable method of testing 
