For many technicians, parallel bars on a frame ruler are essential, especially for all rimless and supra frames. The bars concertina down to 28mm and can be easily lifted off if not required. Mono PDs for progressives are probably the single most important lens measurement these days and are a feature of this ruler. This ruler has been designed with the lab technician in mind but will readily find a place on the dispensing desk too.
1. Use the central triangles to check for mono PDs on progressives.
2. Check for fitting cross heights or bifocal seg heights by centering the frame between the horizontal lines and reading off the heights (shown between 45 and 50mm on the HCL/Datum Line).
3. Once OCs have been dotted on the focimeter, you can check for correct PDs on the HCL/Datum line.
4. Use either length of the ruler to measure length to bend or length to screw, either on the frame or on the patient (up to 180mm)
5. You can also use the ruler edge to measure the PD of the patient.
6. Use the HCL/Datum line to centre the frame in order to measure DBL and DCD
1. When you have marked the dummy lenses where you want the fitting cross height or seg heights, lay the frame against the 32mm square grid for an easy way of ascertaining heights relive to Datum/HCL
2. Use the concentric circles (50-70mm) to ascertain uncut diameter required.
3. Side angles can be measured easily and accurately. The most common angles have been significantly extended on the rule to enhance accuracy.
4. Check the most common seg diameters with the 3 engraved semi-circles for 25, 28 and 35mm segments.
Made from matt coated stainless steel for high visibility, accuracy and extended life.