Haze Measurement – StellarPro Quick Start

Important Notes:
Taking light and dark references should factor out ambient light. However, for the most reliable results, it is ideal to turn off room lighting, and make sure any computer displays are not directly illuminating the sphere.

• Open the StellarPro program .
• In the side navigation bar, select Haze icon
• Install the total cap (the one without the hole on it) and turn ON the lamp so that the light is imaging into the sphere. In Acquire toolbar -> Device Settings, adjust the integration time, number of scans to average, and XTiming resolution control to optimize the device. Haze requires long integration times, so it is recommended that users start with integration times of ###ms and adjust up or down depending on the location of the amplitude of the trace. Enter the desired time in the integration time input box, then click on the “Int Time (ms)” button next to the input textbox to apply the entered time. If an integration time is too long, the trace will saturate at the maximum 65536 counts for the SCOPE graph (bottom left graph); in this case, run a shorter integration time. It is wise to right click on the dark reference before adjusting integration time, because this releases any previous dark reference taken in the software and prevents mistakes. Averaging increases the measurement time because it takes multiple spectral scans defined by the setting and displays their averaged result; it is recommended to use averaging to improve measurement performance.
  

  The example of the scope graph below is correctly optimized to be just below the saturation limit (65,536 counts). The example of the scope graph below have a flat line on the top, indicating the need to reduce the integration time.

• Take Dark Reference. Be sure sample is removed from holder, and that Total Transmission Cap is secured on the back of the sphere. Turn off
  light source and left click on the Dark reference button or . Note: A dark spectrum is necessary only at the beginning of your measurements for the day or every 30 minutes to ensure accurate results.
• Take Transmission Reference. With sample still removed and Total Transmission Cap attached, turn on light source. Make sure no sample obstructing the path of light. Then left click on the Transmission Reference button .
• Take Total Transmission. Place sample in sample holder. Make sure the port is properly illuminated and Total Transmission Cap is still attached. Then left click on the Transmission button .
• Take Diffuse Transmission Reference. Remove sample, and attach Diffuse Transmission Cap (the cap with the small exit port) to the back of the sphere. Then left click on the Diffuse Transmission button . Tip: For best results, make sure that the light eclipses through this port at the beginning of every session. If the light emits a crescent against the lip of the port, manipulate the lens assembly to try and get a better throughput. It helps to remove the clean-up-cap on the front of the sphere to see what you are doing.
• Take Diffuse Transmission / Calculate Haze. Place sample near or against the front cap in sample holder. Make sure the port is properly illuminated and Diffuse Transmission Cap is still attached. Make sure the light path is normal to the sample. Then left click on the Diffuse Transmission / Calculate Haze button .
• After the 5 measurements are taken, the correct values will be updated on the Data window.
• Repeat the steps of taking Total Transmission and Diffuse Transmission to measure the haze value for different samples.