Parr Instrument 6400 - Manual (Page 52)

6
Standardizations
P a r r I n s t r u m e n t C o m p a n y 50
Table 6-2
Calorimeter Control Limit Values in cal/g When Benzoic Acid is Used as a Test Sample
Accepted heat of combustion taken as 6318 cal/g.
Instrument precision 0.10%.
Control limits based on 99% confidence (3 sigma) values.
Values are in cal/g.
NUMBER OF
OBSERVATIONS
IN A GROUP
UCL FOR THE RANGE
(HIGH – LOW) WITHIN
THE GROUP
UCL FOR THE
RSD WITHIN
THE GROUP
MAXIMUM PERMISSIBLE
DEVIATION OF THE GROUP MEAN
FROM THE ACCEPTED VALUE OR
GRAND MEAN
1 19.0
2 23.3 0.261% 13.4
3 27.5 0.228% 10.9
4 29.7 0.209% 9.5
5 31.1 0.196% 8.5
6 32.1 0.187% 7.7
7 32.9 0.181% 7.2
8 33.5 0.175% 6.7
9 34.1 0.171% 6.3
10 34.6 0.167% 6.0
11 35.0 0.164% 5.7
12 35.3 0.161% 5.5
13 35.7 0.159% 5.3
14 36.0 0.156% 5.1
15 36.3 0.154% 4.9
16 36.5 0.153% 4.7
17 36.8 0.151% 4.6
18 37.0 0.150% 4.5
19 37.2 0.148% 4.3
20 37.4 0.147% 4.2
21 37.6 0.145% 4.1
22 37.8 0.145% 4.0
23 37.9 0.144% 4.0
24 38.1 0.143% 3.9
25 38.3 0.142% 3.8