e-gizmo alexan presensitized board calibration

it's easy to make custom pcb's with presensitized board.

but knowing the right timing is needed for make perfect traces with

good line accuracy.

fig 1. Gel curing lamp as a UV source. installed a timer and lcd display
PIC 16F877a as a controller.

 fig 2. print pcb art on transparency sheet. each test box is 1cm by 1cm.

fig 3. pcb is exposed in 2 minute exposures. aluminum foil is used to mask the remaining
unexposed part.

fig 4. developed pcb.

fig 5. Etched pcb. number 6 is perfectly exposed.
while 2 - 4 is under exposed, and 8 - 10 is over exposed.