OT-LightWatcher Data Recorder

This device is a small, wearable, battery operated data acquisition system that measures and records 12 important ambient variables of the working environment of persons. Monitored variables include: Light illuminance (Lux), light irradiance in 5 spectral bands (UV, Red, Green, Blue, IR), temperature, barometric pressure, accelerations, and magnetic field strength. The device measures only 20 mm x 50 mm x 10 mm, has a mass of 12 grams, and can operate for several weeks on a single battery charge.

The sampling and recording rate can be set to a value from 0.5 seconds to 30 minutes. A fast recording rate is available for the acceleration variables. Data are stored in Flash memory. Storage capacity is sufficient to record 1 data record per second for 18 hours, or 1 data record per minute for 6 weeks. Recording is toggled on / off with a single push button (push for 2 seconds). This push button serves also as an event marker if pushed for 0.5 seconds. A small LED and a sounder provide feedback to the user.

The device has a USB-2 data interface. Via this interface and a dedicated software program (OT-Sensor), the sensor can be configured for the particular monitoring task, and recorded data can be downloaded to the PC for display, analysis and archiving.

The data logger is powered by a rechargeable Lithium Polymer battery, which is charged via the USB bus. One battery charge enables a stand-by time of up to 3 months and an operational time of days to weeks, depending on the selected recording rate.

ACCESSORIES

Four types of anatomical mounts are currently available for studies with human subjects:

The Eyeglass anatomical interface is based on eyeglasses with zero diopter plastic glasses (several model available). The data logger is attached to one of the sidebars with double-sided adhesive tape. This mount keeps the optical axis of the data logger well aligned with the principal viewing direction of the subject.

Figure 3: Data logger with Eyeglass mount

The Headset anatomical mount is a light-weight mounting platform for the data logger and optional auxiliary devices. The headset is manufactured from stainless steel, has foam rubber padded temporal cushions, and a low weight of 25 grams. The headset guarantees comfort even if worn all day long. It provides good fixation of the sensor relative to the head during typical office work and low to medium impact physical activity, and keeps the optical axis of the data logger well aligned with the principal viewing direction of the subject.

Figure 4: Data logger with Headset mount

The Badge magnetic mount provides an easy, comfortable way to wear the data logger like a badge on a shirt or on a working coat. The optical axis of the data logger will point primarily upwards in vertical direction.

Figure 5: Data logger with Badge mount

The Necklace mount provides an easy, comfortable way to wear the data logger like a necklace. The optical axis of the data logger will point primarily upwards in vertical direction.

Figure 6: Data logger with Necklace mount

Download: OT-LightWatcher Datasheet