Star Lab GuardOne Manuel page 30

Operation
Operating the Display Area
Bacterial destruction through UV irradation
UV light helps removing (or reducing the number of) airborne microorganisms from a closed environment. It is proven that UV light destroys
almost all DNA-based microorganism given a sufficient UV dosage and irradiation time. But many variables like airflow, humidity, distance of
microorganisms to UV light or UV dosage are present in a real-world environment that make actual calculation of the irradiation time very difficult.
Before performing the steps to adjust the UV 254 Decon, refer to the calculation example for the minimum irradation time, including the formula
as well as the table of recommended times for decontaminating minimum from common organisms.
The germicidal destruction rate is calculated as follows:
Microwatt seconds/cm² = microwatts/cm² x seconds of exposure
The bacterial destruction chart below indicates the amount of shortwave (254 nm) UV energy required for complete destruction of various organisms.
Please note that optimal working conditions are required for the recommended duration of irradiation.
Changing only one factor results in a changed required irradiation time.
Bacteria
Bacillus anthracis
Bacillus megatherium sp. (veg.)
Bacillus megatherium sp. (spores)
Bacillus parathyphosus
Bacillus subtilis (veg.)
Bacillus subtilis (spores)
Clostridium tetani
Corynebacterium diphtheriae
Eberthella typhosa
Escherichia coli
Micrococcus candidus
Micrococcus sphaeroides
Mycobacterium tuberculosis
Neisseria catarrhalis
Phytomonas tumefaciens
Proteus vulgaris
Pseudomonas aeruginosa
Pseudomonas fluorescens
Salmonella enteritidis
Salmonella sp.
Salmonella typhimurium
Sarcina lutea
Serratia marcescens
Shigella paradysenteriae
Spirillum rubrum
Staphylococcus albus
Staphylococcus aureus
Streptococcus hemolyticus
Streptococcus lactis
Streptococcus viridans
30
· GuardOne · Manual
®
Required Microwatt (µW) seconds/cm²
8700
2500
5200
6100
11000
22000
22000
6500
4100
6600
12300
15400
1000
8500
8500
6600
10500
6600
7600
10000
15200
26400
6160
3200
6160
5720
6600
5500
8800
3800
Recommended minimum exposure time
in minutes in 1 m distance by a UV-C power
of 48 µW/cm²
3
1
2
2
4
8
8
2
1
2
4
5
0
3
3
2
4
2
3
3
5
9
2
1
2
2
2
2
3
1