THE BROWN-DUVEL MOISTURE TESTER. 
27 
trial until one or more compartments show the correct heating time. 
If, on the other hand, the 450 cubic centimeters of oil show a heating 
time of more than 20 minutes to reach 175° C, the needle holes in 
the bases of the burners should be opened as explained in item 6 
following. Repeat the oil test, opening or closing the needle holes 
after each test until one or more compartments have the correct heat- 
ing time. For all heating time trial tests use oil at room temperature, 
and in every instance the machines should be given time to cool 
thoroughly before the next trial test is made. 
GAS PRESSURE REGULATOR 
•Screw cover 
Air vent in cover 
Upper f/oaf- 
< Upper float casting 
Mercury sea/ 
lower f /oaf 
mmsm 
Lower float casting. 
Fig. 20. — Sectional view of one form of gas pressure regulator 
(6) When the preliminary adjustments have been made so that 
one or more burners of each moisture tester will heat the 450 cubic 
centimeters of oil to a temperature of 175° C. in 20 minutes, the 
remaining burners should be adjusted, with the corrected burners as 
a standard, to show the correct heating time. These adjustments are 
made by opening or closing the needle hole in the base of the burner. 
If the burner is too fast, the hole may be closed by lightly tapping 
the top of the base with a small hammer or any blunt tool. If the 
burner is too slow, the hole may be opened with a suitable reaming 
tool, such as the fine brooch used by jewelers. 
