PASCO CI-9784 UVA LIGHT SENSOR - Manual (Page 2)

012-07185B
2
UVA Light Sensor
Interface 500
1 2
GAIN=1,10:ISOLATED GAIN = 1,10: REF TO GND GAIN = 1: REF TO GND
A s C
ON
ANALOG CHANNELS B n
DIGITAL CHANNELS
ScienceWorkshop ™
UV A LIG HT SE NS OR
CI-9 784
10 1 10 0 G A IN
P R E S S T O L O G
®
UV A
LIGHT SENSOR
CI- 97 84 10 1 100 GAIN
P R E S S T O L O G
Interface 500 ®
1 2
GAIN=1,10:ISOLATED GAIN = 1,10: REF TO GND GAIN = 1: REF TO GND
A s C
ON
ANALOG CHANNELS B n
DIGITAL CHANNELS
ScienceWorkshop ™
Vacuum UV, UVC and UVB radiation has harmful, high
photon energies and can initiate chemical processes
including changes in biological tissue called photo-
biological reactions.
Reaction-causing UV is also called actinic ultraviolet. It is
characterised by photon energies above about 4 electron
volts (eV). To compute the photon energy in eV from the
wavelength in nanometers (nm) the following formula
can be used:
E eV = 1240
λ(
nm )
For example 315 nm radiation has a photon energy:
E = 1240
315 ≈
3.9 eV
UVA is the least hazardous ultraviolet radiation and its
band extends from 315-400 nm.
It is worthwhile noting that ordinary glass cuts off some
UV radiation with wavelengths less than about 300 nm.
Thus UVA and some UVB can pass through glass.
In addtion to the CI-9784 UVA Light Sensor, an
appropriate UV light source is required in order to
perform some experiments and demonstrations. The use
of a source which radiates in the UVA band is
recommended because it is the least hazardous UV
radiation to work with. A small fluorescent “black” light
makes a suitable UVA source.
Other good sources of UVA radiation are:
• the sun (best on clear days - but some UV when
overcast)
• sun lamps for tanning
• halogen lamps which are not “UV-protected”
• fluorescent lamps
Equipment
INCLUDED
• UVA Light Sensor
• UVA filter and retaining cap
• collimator
• 6-foot cable with 8-pin DIN connectors
ADDITIONAL REQUIRED
• PASCO Interface
• PASCO Data Acquisition Software
Figure 1
Connecting the Light Sensor and the computer interface
B A
ADDITIONAL RECOMMENDED
• UVA Light Sensor Accessory Kit (PASCO
part no. CI-9792)
• 365nm Filter Accessory (PASCO part no.
CI-9841)
Operation
Setting up the Equipment
Connect the UVA Light Sensor unit to analog channel A,
B, or C of the PASCO interface using the cable with the
DIN connectors (Figure 1). Alternatively, the unit can be
plugged directly into the analog channel jack.
Using the Filter With Retaining Cap
The UVA Light Sensor is shipped with the filter installed
in the retaining cap. When the filter is removed from the
retaining cap, light from a wider source can be detected.
Simply unscrew the retaining cap from the photodiode
assembly as neededto remove the filter. See Figure 2. Be
careful not to damage the filter.
photodiode
assembly
Figure 2
Assembly of the Filter and Retaining Cap
UVA filter
retaining
cap
Plug into
any analog
channel.
Plug into
any analog
channel.