Precision Optical Lens Clock Base Curve Gauge (2 Jewels) - Diopter Spherometer

The Precision Optical Lens Clock Gauge (2-Jewel Spherometer) is an essential diagnostic and inspection instrument designed to measure the base curvature, surface radius, and dioptric power of optical eyeglass lenses.

Calibrated to standard optical refractive index n = 1.53, this dial gauge features a highly sensitive 2-jewel movement and three durable contact pins to deliver fast, accurate, and repeatable readings for optometrists, optical labs, and lens manufacturing facilities.

Key Features

• High-Precision 2-Jewel Movement: Minimizes internal friction for ultra-smooth needle response and accurate ±20 diopter measurements.
• Standard Optical Calibration: Calibrated for standard ophthalmic lenses (refractive index n = 1.53) with clear dual-direction (+ / -) dial graduation.
• Durable Stainless Steel Construction: Premium stainless steel body and precision-ground probe tips ensure long-lasting wear resistance and measurement integrity.
• Compact & Portable: Pocket-sized 50 mm dial with a protective hardshell storage case for convenient benchtop or field use.

How to Use

• Step 1 (Zero Calibration): Place the three contact pins vertically on a completely flat surface to ensure the needle points precisely to 0.
• Step 2 (Front Curve): Press the pins perpendicular to the front surface of the lens to record the front curve value.
• Step 3 (Back Curve): Press the pins perpendicular to the rear surface of the lens to record the back curve value.
• Step 4 (Calculation): The true dioptric power / base curve is calculated from the difference between the two readings.

Technical Specifications

• Product Type: Optical Lens Clock / Base Curve Spherometer
• Jeweled Bearings: 2 Jewels
• Body Material: Stainless Steel
• Calibrated Refractive Index: n = 1.53
• Measurement Range: 0 to ±20 D
• Dial Diameter: 50 mm
• Overall Dimensions: 59 mm × 50 mm
• Product Weight: 65 g (0.065 kg)
• Packaging Dimensions: 73 mm × 86 mm × 33 mm
• Package Includes: 1 × Lens Clock Gauge, 1 × Protective Storage Case