Formulas Flashcards
Retention of safety formulas
1
Q
Standard deviation
A
Standard deviation is the square root of the sum(number-mean)squared/number of data-1
SD= ,/€(X-M)2/n-1
2
Q
Mean
A
Average
3
Q
Median
A
Middle
4
Q
Mode
A
Most common
5
Q
How many fall within 1 point of SD? 2 points? 3 points?
A
68%
95%
98%
6
Q
Time weighted average
A
((C1×T1)+(C2×T2)….)/ Tt
7
Q
Accident frequncy
A
LTI/total hours worked x 200000
8
Q
Accident severity
A
LTD/total hours worked x 200000
9
Q
Wet bulb globe temperature indoors
A
WBGT=0.7TWB+0.3TG
10
Q
Wet bulb globe temperature outdoors
A
WBGT= 0.7TWB+0.2TG+0.1TDB
11
Q
Sample volume
A
SV=LOD/(EL×F)
12
Q
Air sampling - air flow LEV
A
Q=V×A
13
Q
Air sampling - dilution ventilation
A
N=(60×Q)/vol
N- air exchange rate
Q- dilution air flow rate(cfm)
Vol- building enclosure volume
14
Q
Duct total pressure
A
TP=VP+SP
TP- TOTAL PRESSURE
VP- VELOCITY PRESSURE
SP- STATIC PRESSURE
