Optometry Equipments, PD Meter/PD Ruler
PD-28
Range of measurement: 45 to 82MM (both eyes), 22.5 to 41MM (each eye)
Indication error: ≤0.5 mm
Rounding error: ≤0.5 mm
Range of focusing point: 30 cm~∞
Electric Voltage: DC 3V (5#AA battery×2 pieces)
Time of automatic shut-off: 1 minute





