Product

• Lotem^® 400
• Lotem 400 Xpose
• Lotem 200K

Background

The objective of the Intensity test is to find the required laser intensity for optimal exposure at a resolution of 100 dpm, and the drum speed value required to obtain optimal intensity.

Note: Test results depend on the plate type, so this test must be performed for each plate type that the customer uses. Test results do not depend on plate size or thickness.

Requirements

Procedure

1. Load a plate.
2. Open the Lotem Calibration dialog box:
• For Lotem 400 Xpose—on the Xpose Utilities panel, double-click LotemCalib.
• For Lotem 400—proceed as follows:
1. In Brisque, from the Launch Pad, open the Setup panel, and then double-click Devices.
2. In the Output Device Handling dialog box, in the Device section, select Plate Setter > Lotem > Lotem400.
3. In the Operations section, select Lotem Calibration.
3. In the Lotem Calibration dialog box (example shown for Lotem 400 Xpose), in the Calibration Type list, select Intensity. The Current Plate type and Plate Sensitivity parameters of the plate that you loaded are automatically transferred from Lotem Controller.
   
4. Define the Plate Policy:
• Load plate—Automatically loads a new plate before the test begins. If you clear this option, you can reuse the plate for additional calibration tests.
• Unload plate—Automatically unloads the plate after the test. If you clear this option, you can reuse the plate for additional calibration tests.
5. Define the Image offset values:
   
   • Horizontal offset—The value around the drum in mm
   • Vertical offset—The value along the drum in mm
   If you use the same plate for several tests, define different offset values for each test.
   Note: The (0,0) offset coordinate is located at the upper-left corner of the plate.
6. Select the required value from the Resolution list.

Note: Do not modify the value in the Intensity box at this time.

7. In the Drum Speed box, type the recommended drum speed value according to the plate type.
   Note: The optimal drum speed value is the drum speed value with which the optimal intensity is obtained.
   
8. Clear the Calculate All Points when Saving check box. The working conditions are updated for the resolution defined in the Resolution box only.
9. In the Test Intensity Values area, define the desired intensity range in the From and To boxes.
   Note: The recommended range is 180 mW to 300 mW.
10. From the Number of steps list, select the required number of exposures for the test intensity values range.
    The size of the step interval is automatically calculated (size of step=[To - From]/[Number of Steps - 1]) and is displayed in the Size box. This value is intended as a quick reference for the Lotem operator, and cannot be modified.
• If the test results are not acceptable, change the value in the Drum Speed box as required, and repeat the test.
• If the test results are acceptable, proceed to step 11.
11. In the Intensity box, type the value of the laser intensity that produces the best exposure.
    
12. Click Save. The new intensity and drum speed values are automatically transferred to the Lotem Controller application.

Technical contact(s)

Content owner: Mario Amir
See the Escalation page for escalation contacts.

Date submitted

16 Nov 2003