1. Introduction
This manual provides instructions for the proper use and maintenance of the Mitutoyo 193-111 Digit Outside Micrometer. This precision instrument is designed for accurate outside diameter (OD) measurements.
Micrometers are precision measuring instruments that utilize a calibrated screw to measure small distances. These measurements are converted into rotations of the screw, which are then read from a scale or a digital display. They are commonly employed in manufacturing, machining, and mechanical engineering for various dimensional measurements.
The Mitutoyo 193-111 features a mechanical digit counter for direct reading, a vernier scale for fine measurements, a ratchet-stop mechanism to ensure consistent measuring pressure, and carbide-tipped measuring faces for enhanced durability and wear resistance. The micrometer's frame has a baked enamel finish for protection, and the thimble and sleeve have a satin chrome finish to resist rust and reduce glare.
Figure 1: Mitutoyo 193-111 Digit Outside Micrometer
This image displays the Mitutoyo 193-111 Digit Outside Micrometer, highlighting its C-frame, thimble, sleeve, and mechanical digit counter. The micrometer is shown with its measuring faces closed, ready for use.
2. Key Components
Understanding the parts of your micrometer is essential for correct operation:
- Frame: The main body of the micrometer, typically C-shaped, with a baked enamel finish for durability.
- Anvil: The stationary measuring face, carbide-tipped for wear resistance.
- Spindle: The movable measuring face, carbide-tipped, which advances or retracts as the thimble is rotated.
- Sleeve: The stationary barrel with the main scale markings (metric units).
- Thimble: The rotating part with the vernier scale markings and a satin chrome finish to resist rust and reduce glare.
- Ratchet Stop: Located at the end of the thimble, it ensures uniform measuring pressure for consistent readings.
- Mechanical Digit Counter: Provides a direct numerical reading for ease of use and precision to 0.01mm.
- Lock Nut: Used to secure the spindle in position after a measurement is taken.
Figure 2: Internal Components of a Micrometer
This image shows various disassembled components of a micrometer, illustrating the intricate parts that contribute to its precision measurement capabilities. This helps in understanding the internal mechanism.
3. Setup and Preparation
- Unpacking: Carefully remove the micrometer from its protective plastic case.
- Cleaning: Before first use, gently wipe all measuring surfaces with a clean, lint-free cloth. Ensure no dust or debris is present on the anvil or spindle faces.
- Temperature Stabilization: Allow the micrometer to stabilize to the ambient temperature of the measurement environment for accurate readings.
- Zero Point Adjustment:
- Clean the measuring faces thoroughly.
- Gently close the measuring faces by rotating the ratchet stop until it clicks 2-3 times. Do not overtighten.
- Check if the '0' mark on the thimble aligns with the datum line on the sleeve, and the digit counter displays '0.00'.
- If adjustment is needed, use the provided wrench to turn the sleeve until the '0' mark aligns. For the digit counter, refer to the specific adjustment procedure in the detailed manual if misalignment occurs (not typically user-adjustable without specialized tools).
4. Operating Instructions
- Holding the Micrometer: Hold the frame firmly but gently in one hand.
- Positioning the Workpiece: Place the object to be measured between the anvil and the spindle.
- Advancing the Spindle: Rotate the thimble to bring the spindle close to the workpiece. For final contact, use the ratchet stop.
- Applying Measuring Pressure: Rotate the ratchet stop until it clicks 2-3 times. This ensures consistent and repeatable measuring force, preventing over-tightening and deformation of the workpiece or micrometer.
- Locking the Spindle: Once the measurement is taken, gently tighten the lock nut to secure the spindle position. This prevents accidental movement while reading the measurement.
- Reading the Measurement:
- Digit Counter: Read the main measurement directly from the mechanical digit counter (e.g., 12.34 mm).
- Sleeve Scale: Read the millimeter (mm) value from the edge of the thimble against the sleeve. Each major line represents 1mm, and each minor line represents 0.5mm.
- Thimble Scale: Read the hundredths of a millimeter (0.01mm) value from the thimble scale where its line aligns with the datum line on the sleeve.
- Vernier Scale (if applicable): For models with a vernier scale on the sleeve, read the thousandths of a millimeter (0.001mm) by finding the line on the vernier scale that aligns perfectly with a line on the thimble scale. Add this value to the sleeve and thimble readings.
- Releasing the Workpiece: Loosen the lock nut and carefully retract the spindle before removing the workpiece.
5. Maintenance and Care
- Cleaning: After each use, wipe the micrometer clean with a soft, lint-free cloth. For stubborn grime, use a small amount of instrument cleaning fluid.
- Lubrication: Periodically apply a thin film of rust-preventative oil to all unpainted metal surfaces, especially the spindle, to prevent corrosion. Avoid over-lubrication.
- Storage: Store the micrometer in its original plastic case in a dry, clean environment, away from direct sunlight, extreme temperatures, and corrosive substances. Ensure the measuring faces are slightly open to prevent pressure on them.
- Handling: Avoid dropping or subjecting the micrometer to impact, as this can affect its accuracy.
- Calibration: Regular calibration by a qualified technician is recommended to ensure continued accuracy, especially in professional settings.
6. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Inaccurate readings |
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| Spindle difficult to turn |
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| Digit counter misalignment | Internal mechanism issue | Contact Mitutoyo service or authorized repair center. |
7. Specifications
| Feature | Detail |
|---|---|
| Model Number | 193-111 |
| Measurement Range | 0-25mm |
| Graduation/Resolution | 0.001mm |
| Accuracy | ±0.002mm |
| Display Type | Mechanical Digit Counter and Vernier Scale |
| Measuring Faces | Carbide-tipped, flat |
| Pressure Mechanism | Ratchet Stop |
| Finish | Baked enamel frame, satin chrome thimble/sleeve |
| Product Dimensions | 6.7 x 3.6 x 1.4 inches |
| Item Weight | 12.8 ounces |
| Material | Carbide (faces) |
8. Warranty and Support
For warranty information, technical support, or service inquiries, please contact Mitutoyo America Corporation directly or visit their official website. Keep your purchase receipt as proof of purchase.
Mitutoyo America Corporation: www.mitutoyo.com
Mitutoyo manufactures precision measuring tools, metrology equipment, and systems. The company was founded in Tokyo in 1934 and formed Mitutoyo America Corporation in 1963, headquartered in Aurora, IL.
