Ocean Optics WS-1 User Manual

WS-1 Reflectance Standard

Operating Instructions

The WS-1 Diffuse Reflectance Standard is for use in performing diffuse reflectance measurements,
especially color analysis. The WS-1 is available in the following four models:

WS1 Diffuse Reflectance Standard

Made of PTFE, a diffuse white plastic that provides a Lambertian reference
surface for reflectance experiments. The WS-1 comes in an anodized
aluminum housing, and is hydrophobic, chemically inert and very stable,
even in deep-ultraviolet applications. It is >98% reflective from 250­1500 nm and >95% reflective from 250-2200 nm.

The reflective area of the WS-1 has a 32 mm OD. The diffusing material is
encased in a small receptacle with screw-on top. The material is almost
uniformly reflective (>95%) by wavelength across the entire range of 250­2000 nm.

WS-1-SL White Reflectance Standard

The WS-1-SL is a diffuse reflectance standard from Labsphere and is made
from their patented diffuse reflectance material, Spectralon. Spectralon is
hydrophobic and is thermally stable to 350 °C. The durable material
provides highly accurate, reproducible data. Unlike all the other PTFE­based standards on this page, the WS-1-SL often can be smoothed, flattened
and cleaned if nicked or soiled.

WS-1-SS White Standard with Stainless Steel Housing

The WS-1-SS comes in a stainless steel housing and has the same properties
as the WS-1. In addition, the surface of the WS-1-SS is slightly recessed to
allow the RPH-1 Reflection Probe Holder to sit on the standard without
coming in direct contact with the standard’s surface.

WS-3-GEM White Standard

Conceived for use in colorimetric applications involving diamonds and
other gems, the WS-3-GEM White Reference Tile consists of a diffuse
PTFE-based material, shaped to form a holder within its stainless steel
receptacle. Because of its concave shape, the WS-3-GEM becomes an
integrating sphere when illuminated.

The WS-3-GEM has >98% reflectivity from 400-1500 nm and >95%
reflectivity from 250-2000 nm. Like the WS-1, the WS-3-GEM's
reflectance material is hydrophobic, chemically inert and very stable, even
in deep-UV applications.

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WS-1 Operation Instructions

201107

Operation

Reflection is the return of radiation by a surface, without change in wavelength. Reflection is expressed as
a percentage relative to the reflection from a standard substance, such as the WS-1 white reference
material. The WS-1 is mostly used in a setup with a reflection probe and reflection probe holder for
diffuse reflection measurements.

Operating Using OOIBase32 Software

► Procedure

1. Make sure you are in Scope mode, by either clicking the Scope Mode icon on the toolbar, or
selecting
the light path going to your reference. Place the reflection probe over the reflection standard.
Keep the reflection probe at an angle between 0 and 45

2. Click the Store Reference spectrum icon on the toolbar or select Spectrum | Store Reference

from the menu bar to store the reference. This command merely stores a reference spectrum in
memory. You must select
spectrum to disk.

View | Scope Mode. Take a reference spectrum by first making sure nothing is blocking

.

File | Save | Reference from the menu bar to permanently save the

3. Block the light path to the spectrometer. Then, take a dark spectrum by clicking the

Spectrum

command merely stores a dark spectrum in memory. You must select
menu to permanently save the spectrum to disk.

You must take a dark spectrum before measuring transmission.

4. Put the sample is in place and ensure that the light path is clear. Then, take a reflection
measurement by clicking on the

Transmission Mode

transmission and reflection are identical). To save the spectrum to disk, click the
toolbar or select

icon on the toolbar or by selecting Spectrum | Store Dark from the menu bar. This

File | Save | Dark from the

Transmission Mode icon on the toolbar or selecting Spectrum |

from the menu bar (since the mathematical calculations used to calculate

Save icon on the

File | Save | Processed from the menu bar.

Operating Using SpectraSuite Software

► Procedure

1. Place SpectraSuite in Scope mode by clicking the Scope ( ) icon in the Experiment mode
toolbar or selecting

2. Ensure that the entire signal is on scale. The intensity of the reference signal’s peak differs
depending on the device being used. If necessary, adjust the integration time until the intensity is
appropriate for your device. Ensure that the entire signal is on scale.

3. Select

File | New | Reflection Measurement. Use the Reflection Measurement wizard to take a
reference spectrum (with the reference standard) and a dark spectrum. You must take a reference
and a dark spectrum before measuring reflection.

Processing | Processing Mode | Scope from the menu.

Store Dark

4. Put the sample in place and ensure that the light path is clear. Then, take a reflection
measurement.

5. If you received calibration file with your reference standard, click the Non-unity Correction icon

) on the toolbar. The Select Reference File screen appears.

(

6. Browse to the location where you stored your reflectivity standard files. Then click the
button.

The reference information appears on the

2 A367-DS-1-01-

Apply

Select Reference File screen.