User's Manual

C-6 Actiwatch Hardware
Recommended Calibration
We recommend factory calibration of Actiwatch-L every 12 months. Contact
Mini Mitter Technical Support for information.
Inuences
There are various factors that may influence the light (illuminance) data collected
by Actiwatch-L. The most likely to occur are as follows.
Sensor positioning
The angle at which light impacts Actiwatch-L can result in variations in readings.
This is true of all light sensing devices. It is important that researchers develop
astandardizedlocationonthesubjecttoenableActiwatch-Ltominimizethis
variable.
Condition of the lens
Light (illuminance) measurement varies greatly with a buildup of materials on
the lens. It is important to check for dirt, moisture, and other obscuring debris
prior to initiating data collection. Keeping the device clean will help avoid this
problem. Clean as you would eyeglasses, with a soft cloth moistened with water.
Inadvertently covering Actiwatch-L
The light sensor may inadvertently be covered by clothing or other items. The
unit may be detached from the band and used on a visor or other piece of clothing
tominimizethispossibility.Analysisofdatashouldalwaystakethesevariables
into account.
Illuminance Data
Illuminance data (“light data”) retrieved from Actiwatch-L are stored in the
Actiware database along with activity data. Illuminance data are expressed in the
SI (System International) unit of lux (see “Definitions for Actiwatch-L” on the
following page).
Light Analysis is integrated seamlessly into Actiware. Instead of having a
separatewindowforanalyzingilluminancedata,theActogram, Graph, Data List,
and Statistics Table can be used for light analysis.
Actiwatch-L Actogram Data