Technical parameters: 1. Measuring point spherical design, suitable for measuring the thickness of the shell surface 2. Resolution: 0.01mm 3. Range: 0-10.0mm 4. Power source: 1.5V button battery (SR44 / LR44) 5. Operating temperature: 0-40 ℃ 6. Storage temperature: -20-70 ℃ 7. Relative humidity: ≤80% Features: 1. ZERO key resetting at any position in order to differential measurements; 2. OFF / ON key to open automatically turns the screen; 3. INCH / MM measurement standard conversion key; 4. Suitable Measurement eggs, duck, goose and other shell thickness 5. Simple to operate, reliable methods of operation: 1. OFF / ON key, turn on the tester (press again to close the tester); 2. Press ZERO clear zero. 3. Press down on the knob to lift the table, raised test head, placed in the test shell (endometrial eggshells first stripped before testing) 4. Loosen the knob lift table, the test head down, pressing the sample, 5. The test results show INCH / MM key, convert units of measurement in inches or mm;