Transcript Document

CONSTRUCTION OF A SENSOR TO QUANTIFY THE
GROWTH OF MOULD IN BUILDINGS
Background
Indoor mould is important, in terms
of health and financial costs. 10%
of Canadian children are asthmatic
and this is strongly correlated with
indoor mould growth. How can
mould growth be sensed?
Controller
PCB
housing
Battery holder Wireless
PCB
Optical
PCB
Light
baffle
Location of
membrane
Model of mould sensor
Catastrophic mould
contamination of a home
Objective
To build a miniature sensor for
quantification of mould biomass
through a calibration against light
reflectance. Installation of the
device onto building surfaces and
remotely polling intermittently to
assess growth rates.
Research Carried Out To Date
Printed circuit boards (PCBs)
and a housing unit have been
designed and fabricated. The
sensor’s accuracy has been
tested as compared to a
scanning method.
LED
photodiode
base
body
lid
Mould
on PVC
membrane
microcontroller
The housing unit, optical PCB, and
controller PCB that were fabricated and a
sample of a PVC mould membrane
4.500
Outcomes To Date
Output Voltage (V)
4.000
3.500
3.000
2.500
2.000
1.500
1.000
50
100
150
200
Grey Scale
Scanned data compared with
sensor data for PVC membranes
250
Photodiode output data from
the sensor circuit show
excellent agreement with
those obtained by placing the
mould membranes on a
flatbed scanner.