Vernier Go Direct GDX-POL Manual page 3

Exposing the sensor to temperatures below –15°C or over 45°C will damage the
sensor. Additionally, temperatures over 35°C (95°F) will reduce the battery's
lifespan. If possible, store the device in an area that is not exposed to
temperature extremes.
Water Resistance
Important: Go Direct Polarimeter is neither waterproof, nor is it water resistant
and should never be immersed in water.
If any liquid gets into the device, immediately power the unit down (press and
hold the power button for more than three seconds). Disconnect the sensor and
charging cable, and remove the battery. Allow the device to dry thoroughly
before attempting to use the device again. Do not attempt to dry using an
external heat source.
Note: Damage due to liquids is not covered under warranty.
How the Sensor Works
Go Direct Polarimeter is a vertical polarimeter that uses an LED source, a fixed
polarizer, and a rotating polarizer (also called an analyzer) to detect changes in
rotation of plane-polarized light in the presence of an optically active
compound. Go Direct Polarimeter uses a light sensor and a bidirectional optical
encoder to detect the quantity of light passing through the sample at each angle
as the analyzer is rotated by a motor. A graph is produced that shows a clear
change in the light's polarization with respect to angle. This allows the user to
determine various characteristics, including the identity, of the specific chemical
compound being investigated.
Incident non-polarized light is transmitted through a fixed polarizer that only
allows a certain orientation of light into the sample. The sample then rotates the
light at a unique angle. As the analyzer is turned, the rotated light is maximally
transmitted at that unique angle, allowing the user to determine properties of the
sample. A (+) enantiomer rotates the plane of linearly polarized light clockwise,
dextro, as seen by the detector. A (–) enantiomer rotates the plane counter-
clockwise, levo.
Troubleshooting
Due to the nature of light transmission, it is important that the sample be
l
transparent and homogeneous. The sample can have a moderate amount of
color (up to OD of 2) but make sure it is not too dark to ensure that light
will still pass through it onto the detector.
The illumination value should not be used as a quantitative value for this
l
device. If you choose to use it for this purpose, note that this value is very
sensitive to change. These slight variations can be brought on by several
different variables in the sample including inhomogeneity (such as
particulates and bubbles), height of the sample in the cell, concentration of
the sample, and aberrations in the glass cell or pathlength.
The standard in polarimetry is to use a 10 cm pathlength. However, since it
l
is not always feasible to have this large of a sample volume, you can
accurately take readings with sample heights lower than 10 cm. To remain
within the ±1° accuracy of the device, keep sample heights between 2 cm
(~5 mL) and 10 cm (~ 25 mL). Outside of this region, there can be
deviations in the light path that decrease the accuracy of the detector.
A package of four additional sample cells is available. Order code: CELLS-
l
POL.
For troubleshooting and FAQs, see
Repair Information
If you have followed the troubleshooting steps and are still having trouble with
your Go Direct Polarimeter, contact Vernier Technical Support at
support@vernier.com or call 888-837-6437. Support specialists will work with
you to determine if the unit needs to be sent in for repair. At that time, a Return
Merchandise Authorization (RMA) number will be issued and instructions will
be communicated on how to return the unit for repair.
Accessories/Replacements
Item
Chemical Polarimeter Accessory Cells
Go Direct 650 mAh Replacement Battery
Micro USB Cable
Warranty
Warranty information for this product can be found on the Support tab at
www.vernier.com/gdx-pol
General warranty information can be found at
Disposal
When disposing of this electronic product, do not treat it as household waste. Its
disposal is subject to regulations that vary by country and region. This item
should be given to an applicable collection point for the recycling of electrical
and electronic equipment. By ensuring that this product is disposed of correctly,
3
www.vernier.com/til/10458
Order Code
CELLS-POL
GDX-BAT-650
CB-USB-MICRO
www.vernier.com/warranty