Lab Spectroradiometer FAQs

What is the spectral range of each spectroradiometer?
PS-100: 350 to 1000 nm
PS-200: 300 to 850 nm
PS-300: 300 to 1000 nm
SS-110: 340 to 820 nm
SS-120: 635 to 1100 nm
What type of spectroradiometer do I need?
The PS series are excellent for spot measurements in the lab or field. They can also be used for spot calculations on reflectance or transmittance. The SS series are designed for either spot measurements in a field or lab as well as long-term deployment in a field or lab for various light studies including reflectance and transmittance.
Where are the calibration files for my PS Series spectroradiometer?
The PS Series spectroradiometer calibration files are located on the USB drive provided with the instrument (sw.ini and sw1.icf).
How do I take a measurement with my PS Series spectroradiometer?

Measuring Photon Flux

  1. Make sure temperature compensation is on: Setup -> Temperature Compensation
  2. Determine the integration time and save a dark scan as described on page 13 of the manual: The First Two Steps for Every Measurement.
  3. View -> Radiometer* and select Watts m-2, µmol m-2 s-1, or lux m-2 as desired.
  4. To look at light intensity at a given wavelength, right-click the cursor at the wavelength. Fine-tune the position of the displayed line using the peak left and right icons.
  5. Save scan. A prompt will ask for a location to be specified for saving. A second prompt shows export parameters, including Starting Wavelength, Wavelength Increment, and Ending Wavelength.

Measuring Reflectance/Transmittance

  1. Determine the integration time and save a dark scan.
  2. Save a reference scan using a reflectance standard as shown in Figure B of the owner's manual. (Vertically mounted fiber optic cable, a light source 45 degrees from vertical, and the reflectance standard laying in a plane perpendicular to the fiber-optic cable.) For reflectance and transmittance measurements, the sample reading is divided by the reference reading to give percent reflectance (transmittance).
  3. View transmittance mode
  4. Save scan with the fiber optic cable held or mounted as shown in Figure C of the owner's manual for reflectance. (Vertically mounted fiber optic cable, a light source 45 degrees from vertical, and the leaf or sample standard laying in a plane perpendicular to the fiber-optic cable.)
  5. See Exporting to Excel in the owner's manual for instruction on importing data into Excel. Data will appear as a .TRM file.

Measuring Absorbance

  1. Determine the integration time and save a dark scan.
  2. Save a reference scan as shown in Figure D of the owner's manual. (A scan with an empty vessel in between the fiber-optic cable and the light source.)
  3. View transmittance mode: View -> Absorbance
  4. Save scan with the fiber optic cable held or mounted as shown in Figure E of the owner's manual. (A scan with the sample in the vessel in between the fiber-optic cable and the light source.) See Exporting to Excel in the owner's manual for instructions on importing data into Excel. Data will appear as an .ABS file.
How do I set the integration time on my PS Series Spectroradiometer?
For each given light source the optical integration time must be determined. The software will prompt the user to restore integration time to default when view mode is changed. Current integration time can kept by selecting Cancel.
  1. Set the view to scope mode: View -> Scope Mode
  2. Set the integration time as high as possible without saturating: Setup -> Detector Integration Time
  3. Adjust integration time by ± 5 ms to check for saturation in the highest peak. The highest peak in the integration time is increased. High saturation appears as a horizontal plateau across the crest of the peak. When saturation occurs, decrease the integration time by 5 ms, ten wait for the vertical line to lengthen and move slightly downward from the top of the window. This may require several adjustments.
  4. Cover the sensor head with a black cap and save a dark scan be selecting the dark spectrum icon. A dark scan should be taken whenever the integration time is changed.
  5. If a view mode such as radiometer is being used, return to that mode. Press cancel to keep current integration time or OK to reset integration time to default.