9.5 
the drift line as follows (see Fig. B4-12): 
UAC 1G CRE 4G 
spay i 
10. 
RELEASE AND RECORDER RECORD B4-31 
Drift and Shift. If there has been a drift as well as a shift, draw 
wee eee : Git 
| 
HO A Ed 
ae JUL [ 1 | LL 44 t4-+ {4 
| 
44th tt Ht +f +44, H jt +H 
i} 
i) 
L a Ht at a 
H 
| if tu i dl : 
jo 
ule tt tt Pitot ttt tt tt TT + iq 
{44 mW qe > 4 Thre 44-4 Tt +++ 4-44 é 
I 11 
hi aa sannil sy etete dota Edd td OTe gE Pa We 
1 
i | 
Peamol i | tdi 0 {3]0 | | /4)0) i 70) | | Oy PET 190} | 3 
Figure B4 - 12. Shift and Drift 
a. Multiply the amount of shift of the temperature ordinate by 
the ordinate of the low reference before the shift, and divide 
the product by the temperature ordinate before the shift, thus: 
C = _TR where C =Correction for shift to be applied to the fol- 
0 
lowing low-reference contact, T = shift of temperature ordi- 
nate, R = low-reference ordinate before shift, and0 = temper- 
ature ordinate before shift. 
b. At the following low reference, place a point an amount equal 
to and inadirection opposite from the computed low-reference 
shift. The difference between this point and the preceding low 
reference is the amount of drift which occurred in addition to 
the shift. Draw the drift line from the preceding low reference 
toward this point, but stop at the level of the shift. Then dis- 
place the drift line the same direction and amount as the com- 
puted low-reference shift. Continue the drift line to the left 
edge of the following low reference. 
Missing Low-Reference Contacts. When one or more low-refer- 
ence contacts are missing, draw the drift line between the first readable 
low-reference contact above and below them. If all the low-reference 
contacts become unreadable, but the high-reference contacts continue 
readable, determine the relationship between the low andhigh references 
Io ih 
69 FMH#3 
