Spectrophotometer Base Connect the Rotary Motion Sensor plugs into the Put the Pinion Science Workshop interface. on the shaft. Mounting the Degree Plate and Light Sensor Arm The Degree Plate and Light Sensor Arm are shipped as a unit.The Light Sensor Arm is Use the thumbscrew attach the senso Rotary Motion attached to the circular Degree Plate with two Sensor small thumbscrews.The hole in the center of the Figure 7:Attach the Sensor and Pinion Degree Plate fits over the short threaded post on the top of the Spectrophotometer Base. Hold the Rotary Motion Sensor slightly away from the base so the small diameter post on top of the Pinion is not in the way of the edge of the Degree Plate Degree Plate.Position the hole in the plate over the short threaded post on the top of the base. m Place the Degree Plate onto the Spectrophotometer Base.Let the small diameter post on the top of the Pinion rest against the edge Let the post on top of the Pinion rest against the of the Degree Plate (see Fig.8). edge of the Degree Plate. More Information About the Degree Figure 8:Degree Plate onto Base Plate The ratio between the radius of the Degree Plate and the radius of the small post on the top of the Pinion is designed to be 60 to 1.In other words,the Pinion rotates 60 times for one rotation of the Degree Plate. This assumed ratio of 60 to 1 is included in a calculation for the actual angular displacement of the Degree Plate as it turns during the measurement of a spectrum (see"Using the Science Workshop Program"in the Procedure section). Using the exact ratio of the Degree Plate to the small Pinion post can slightly improve the accuracy of measurement.To determine the exact ratio of the Degree Plate to the small Pinion post,do the following to calibrate the Degree Plate: 1.Remove the Light Sensor Arm from the Degree Plate by unscrewing the two small thumbscrews. (You can store the thumbscrews in the empty threaded holes on the Light Sensor Arm.)Turn the Degree Plate so the zero degree mark is exactly aligned with the index mark on the arm that extends from the Spectrophotometer Base. 2.Start the Science Workshop program.(See the Science Workshop User's Guide for more information.) 3.In the Science Workshop program,select the Rotary Motion Sensor to be connected to Digital Channels 1 and 2.Set the resolution of the Rotary Motion Sensor to 1440 Divisions/Rotation. >7 Connect the Rotary Motion Sensor plugs into the Science Workshop interface. Mounting the Degree Plate and Light Sensor Arm The Degree Plate and Light Sensor Arm are shipped as a unit. The Light Sensor Arm is attached to the circular Degree Plate with two small thumbscrews. The hole in the center of the Degree Plate fits over the short threaded post on the top of the Spectrophotometer Base. Hold the Rotary Motion Sensor slightly away from the base so the small diameter post on top of the Pinion is not in the way of the edge of the Degree Plate. Position the hole in the plate over the short threaded post on the top of the base. Place the Degree Plate onto the Spectrophotometer Base. Let the small diameter post on the top of the Pinion rest against the edge of the Degree Plate (see Fig.8). More Information About the Degree Plate The ratio between the radius of the Degree Plate and the radius of the small post on the top of the Pinion is designed to be 60 to 1. In other words, the Pinion rotates 60 times for one rotation of the Degree Plate. This assumed ratio of 60 to 1 is included in a calculation for the actual angular displacement of the Degree Plate as it turns during the measurement of a spectrum (see “Using the Science Workshop Program” in the Procedure section) . Using the exact ratio of the Degree Plate to the small Pinion post can slightly improve the accuracy of measurement. To determine the exact ratio of the Degree Plate to the small Pinion post, do the following to calibrate the Degree Plate: 1. Remove the Light Sensor Arm from the Degree Plate by unscrewing the two small thumbscrews. (You can store the thumbscrews in the empty threaded holes on the Light Sensor Arm.) Turn the Degree Plate so the zero degree mark is exactly aligned with the index mark on the arm that extends from the Spectrophotometer Base. 2. Start the Science Workshop program. (See the Science Workshop User’s Guide for more information.) 3. In the Science Workshop program, select the Rotary Motion Sensor to be connected to Digital Channels 1 and 2. Set the resolution of the Rotary Motion Sensor to 1440 Divisions/Rotation