7
Measure an Emission Spectrum with LabQuest
You may use your Spectrometer to measure the emission spectrum of a light source
such as an LED or a gas discharge tube. To do so, you will need to purchase an
optical fiber assembly (order code: VSP-EM-FIBER).
Measure Intensity of Light Emissions
1. Use a small screwdriver to loosen the two screws that connect the cuvette holder
to the Spectrometer (see Figure 1). Remove the cuvette holder and connect an
optical fiber assembly to the Spectrometer.
2. Use a USB cable to connect the Spectrometer to your computer.
3. Start Logger
Pro
3.
4. On the Meter screen, tap Change Units
►
USB: Spectrometer
►
Intensity from
the Sensors menu. Intensity is a relative measure with a range of 0–1.
Note:
The
Spectrometer is not calibrated for measuring intensity.
5. Aim the tip of the optical fiber at a light source. Start data collection. Tap the red
Stop button to end data collection.
If the spectrum maxes out (flat and wide peaks at a value of 1), increase the distance
between the light source and the tip of the optical fiber cable or reduce the sample
time (see Change the Settings in LabQuest below).
To increase the sample time, or if data collection is unusually slow, choose Set Up
Sensors
►
Spectrometer: 1 from the Experiment menu. Set the Sample Time (begin
with 75 ms, with subsequent reductions by 20 ms) to a suitable value and decrease
the Samples to Average to 1.
Change the Settings in LabQuest
Data Collection Screen
The Data Collection Screen in LabQuest lists all the settings for the device. To
display this box choose Sensors
►
Data Collection from the Meter screen.
For most experiments, the default settings work well.
There are four parameters listed in the dialog box.
Sample
Time: this is similar to the shutter speed of a camera. LabQuest
automatically selects the proper sample time during calibration.
Note:
For
emission studies, you may need to change the sample time manually.
Wavelength Smoothing: the number of adjacent readings on either side of a given
value that is used to calculate an average value.
Note
: Be careful adjusting this
parameter as it may shift your wavelength values slightly.
Samples to Average: the number of readings taken at a given wavelength to
calculate an average reading.
Wavelength Range: the range is determined by the type of spectrometer in use.
8
Specifications
Dimensions
40.7 mm × 88.8 mm × 34.1 mm
Power consumption
160 mA @ 5 VDC
Light source
Tungsten and violet LED
Detector
Linear CCD
Wavelength range
380 nm–950 nm
Wavelength reporting interval
2 nm
Optical resolution*
3.0 nm
Wavelength accuracy†
± 2.0 nm
Photometric accuracy‡
± 5.0%
Typical scan time
~ 2 s
Operating temperature
15–35ºC
*as determined by the full width of half maximum of Hydrogen 486 nm peak
†as determined with holmium oxide NIST standard
‡as determined with nickel sulfate standards between 0.1-1.0 AU
Lamp Lifetime, Warranty, and Replacement
The light source in the Vernier Spectrometer is a tungsten lamp. The lifetime of
this source is rated at approximately 2000 hours. Lifetime is defined as the amount
of time it takes the lamp to decrease to 50% of its original output.
The lamp is covered by a one-year warranty.
Contact Vernier or Ocean Optics for all repairs and service including lamp
replacement.
No user-serviceable parts are in this device. Do not attempt to open the case of the
device. Do not attempt to change or repair the lamp. Doing so will create an
unsafe operating condition and will void the product warranty.
Warranty
Vernier warrants this product to be free from defects in materials and workmanship
for a period of three years from the date of shipment to the customer. This warranty
does not cover damage to the product caused by abuse or improper use. The light
source is covered for one year.
Vernier Software & Technology
13979 S. W. Millikan Way
Beaverton, OR 97005-2886
Toll Free (888) 837-6437
(503) 277-2299
FAX (503) 277-2440
www.vernier.com
Rev. 6/18/2014
Logger
Pro
, Logger Lite, Vernier LabQuest, Vernier LabQuest Mini, Vernier LabPro, Go!
Link, Vernier EasyLink and
other marks shown are our trademarks or registered trademarks in the United States. All other marks not owned by us
that appear herein are the property of their respective owners, who may or may not be affiliated with, connected to, or
sponsored by us.
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