ELEMENT:
Campbell CR10X datalogger
AIM:
Two Campbell dataloggers are used in the Healthy Home to record information
about water and power use within the house and climatic conditions in
the house and surrounding environment.
One datalogger records information from the rain gauge, a rainwater tank
pressure sensor,15 watermeters and 5 electrical power meters located throughout
the home. The water and power meters are situated in a variety of places
within the home, so that the researchers can assess where the partitioning
of use (e.g. toilet versus laundry; lighting versus pumps etc.) of water
and electricity.
The other datalogger records information on 9 temperature sensors and
7 power sensors throughout the house, relative humidity inside and outside
the house, the amount of sunlight and wind speed and direction from the
weather station on the roof.
The information is recorded every 10 minutes and added up every half
hour and at midnight each night.
The data sent by the sensors and collected in the datalogger is used
to discover where improvements in house design can be achieved. Some of
the data collected is available on the Live Data section of the web site.
STRATEGY:
Optimise Passive Design
The dataloggers are able to acquire, process and log data delivered
from the sensors without direct computer control. The dataloggers in the
house log the relevant information for 10 minutes then stream the information
to the localised computer.
The sensors linked to the data acquisition and logging system are the
water meters, power meters, raingauge, rainwater tank pressure transducer,
wind velocity and direction sensor, thermocouples, pyranometer, and humidity
sensors.
One water meters is placed on each hydraulic circuit within the house.
The water meters are equipped with a switch closure which sends a pulse
to the datalogger for every litre of water used. From this information
the researchers can determine how much water is used at any period throughout
the day and where in the house the water is being used.
Two types of power transducers are utilised at the Healthy Home. The
power output of the PV array and power consumption of the whole house,
hot water system booster and rainwater supply circuit are recorded by
true power meters. Toroid transducers are utilised on seven seperate circuits
throughout the house. A toroid measures the electromagnetic field that
is produced when current flows through the cable, because the actual voltage
fluctuates, data from a toroid has to be calibrated against the true power
used for the period.
The 0.5mm tipping bucket rain gauge is mounted on the apex of the roof.
The data is used to calculate the catch efficiency of the rainwater collection
system.
The pressue transducer in the rainwater tank allows the researchers to
monitor the water level fluctuations due to outflow due to water use and
inflow from the coucil mains top-up or rainwater catch. The water meter
information when combined with the rainfall information and rain tank
information allows the researchers to complete a household water balance
for any period.
The wind velocity and direction sensor is mounted at the highest point
on the roof.
The thermocouples are strategically placed to measure air temperature
and surface temperatures of materials on the inside and outside of the
house. For example air temperatures are measured 1000mm under the ground,
undercroft, ground floor level, 1800mm above ground floor level, floor
level first floor level, 1800mm above first floor level, ceiling height
at first floor level (approx 4500mm), roof surface and inside the Stevenson
Screen (meteorology box positioned on the roof).
The Pyranometer mounted on the roof surface measures solar irradiation
and radiant heat from the sun.
Humidity devices are located in the Stevenson Screen on the roof and
400mm below ceiling height in the living room.
The dataloggers download to the local computer every ten minutes for
data processing and generation of graphics for the web site.
Alarms can be set to the channels providing warning and control signals
for quality control of the system and information being processed.
Top
|
