Product

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

Background

The objective of performing a drum speed test is to determine the drum speed applicable to the required intensity. In the intensity test, drum speed is constant and intensity varies. In the drum speed test, intensity is constant and drum speed varies.

Note: Test results depend on the plate type, so this test must be performed for each plate type that the customer uses.

Requirements

Confirm that the device is calibrated according to the following tests:

• Focus Calibration Test
• Elevation Adjustment procedure
• Intensity Calibration Test
• Resolution Calibration Test
• Delay Calibration Test
• Laser Uniformity Calibration Test

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, on the CDE panel, double-click Devices.
2. In the Output Device Handling dialog box, select Plate Setter > Lotem > Lotem400.
3. On the Operation panel, select Lotem Calibration.
3. In the Lotem Calibration dialog box (example shown for Lotem Xpose), in the Calibration Type list, select Drum Speed.
   
4. Select the plate type:
• For Lotem Xpose—in the Current Plate type dropdown list
• For Lotem 400—in Media
5. Define the Plate Policy:
• Load plate—Automatically loads a new plate before the test begins. If you clear this option, an already-loaded plate is used, and you can reuse a plate for additional calibration tests.
• Unload plate—Automatically unloads the plate after the test. You must load another plate for additional tests. If you clear this option, you can reuse the plate for additional calibration tests.
6. 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, use different offset values for each test.
   Note: The (0,0) offset coordinate is located at the upper-left corner of the plate.
   
7. In the Test Resolution list, select the required resolution.

Note: At this point, do not modify the value in the Drum Speed box.

8. To define the resolutions for which the intensity and drum speed values are updated when you click Save, select the Calculate All Points when Saving checkbox. The updated values are calculated according to the results of the current drum speed test.
   Note: To update intensity and drum speed values for the resolution defined in the Resolution box only, deselect the Calculate All Points when Saving checkbox.
9. In the Test Drum Speed Values (rpm) area, type the values for the drum speed range.
10. In the Number of steps list, type the required number of exposures for the drum speed values range.
    The size of each step interval is automatically calculated and displayed in the Size box.
    Size of step=(To - From)/(number of steps - 1)
    Note: This value cannot be modified. It is intended as a quick reference for the Lotem operator.
11. Click Test to initiate the drum speed test according to the settings.
12. Develop the plate and examine the results.
13. Determine the optimal drum speed value according to the drum speed value of the best exposure. Type this value in the Drum Speed box.
    Note: The optimal intensity value is the intensity value in which the optimal drum speed was obtained.
14. Click Save to save the new drum speed value and the new intensity value. These values are transfered to Lotem Controller.

Technical contact(s)

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

Date submitted

18 Dec 2003