Purpose
To measure light penetration in algal growth
studies. Can be done in conjunction with sediment traps in determining the
effects of turbidity and light extinction on reef algae.
Materials
2K HOBO Light Intensity logger (0.01 to ~10k
lumens/ft2)
BoxCar Pro Starter Kit (Windows) BCP4.3-ON
or BoxCar Starter Kit (Windows) BC3.7-ON
Submersible case, clear
Silicone pack
Overview
A light intensity logger is a small,
battery-powered data logger that is equipped with a microprocessor, data storage
and sensor. The logger records light intensity in specified time increments. The
logger records each measurement and stores it in memory along with the time and
date. Temperature data loggers with similar capabilities are also available.
Deployment
Before being deployed in the field, the Hobo
logger must be initiated. The Hobo logger has limited memory, so the sampling
interval must be determined based upon Hobo memory size and length of
deployment. Connect the Hobo logger to a computer with the supplied cable, start
the BoxCar software, set the sampling interval, then initiate the Hobo. Place
the Hobo into the submersible case with a silicone pack, and carefully replace
the O-ring and cap.
Place the Hobo where it is fully exposed to
available light. Use cable ties or steel cable to attach the data logger to the
substrate or other equipment. After desired time in field, retrieve the logger.
The logger is then reconnected to the personal computer and the software is used
to download the data, which is then displayed in a graph, showing the profile
over time. The tabular data can be viewed as well, or exported to a spreadsheet
for further manipulation.
Contact Information
Onset Computer Corporation
PO Box 3450
Pocasset, MA 02559-3450
1-800-564-4377, (508) 759-9500
Fax: (508) 759-9100
sales@onsetcomp.com
