OTC 3665 Phototach Contact/Non-Contact Tachometer User Manual

1. Introduction

The OTC 3665 Phototach is a versatile instrument designed for accurate measurement of rotational speed (RPM) using both contact and non-contact methods. Its infrared technology ensures precise readings, while the non-contact design minimizes torque loss. This manual provides essential information for the safe and effective operation, maintenance, and troubleshooting of your Phototach.

2. Safety Information

Please read and understand all safety warnings and operating instructions before using this device. Failure to do so may result in injury or damage to the instrument.

• Laser Safety: The Phototach uses a Class II laser. Do not stare directly into the laser beam or direct it at others. Avoid prolonged exposure.
• Rotating Parts: Exercise extreme caution when measuring rotating machinery. Keep hands, clothing, and hair clear of moving parts.
• Battery Handling: Use only the specified battery type. Do not mix old and new batteries. Dispose of batteries properly according to local regulations.
• Environmental Conditions: Do not operate the device in explosive atmospheres or in the presence of flammable gases or vapors. Keep the device dry.
• Maintenance: Refer to the maintenance section for cleaning and care instructions. Do not attempt to disassemble or repair the unit yourself.

3. Product Overview

3.1 Components

The OTC 3665 Phototach kit includes the following items:

• OTC 3665 Digital Tachometer Unit
• Contact Adapter (for contact measurements)
• Four styles of contact adapter tips (e.g., cone, funnel, wheel)
• Reflective Tape (for non-contact measurements)
• Carrying Case
• Operation Manual

Figure 1: OTC 3665 Phototach kit contents. This image displays the main tachometer unit, various contact adapter tips, a roll of reflective tape, and the protective carrying case.

3.2 Key Features

• Dual Measurement Modes: Functions as both a contact and non-contact tachometer.
• Infrared Technology: Provides accurate and convenient non-contact measurements.
• Laser Pointer: Ensures accurate targeting for non-contact measurements.
• Wide Measuring Range: 2.5 to 99,999 RPM.
• High Resolution: For precise readings.
• Large 5-Digit Display: Clear and easy-to-read results.
• Auto Ranging: Automatically adjusts measurement range.
• Min/Max Memory Storage: Records minimum and maximum RPM values.
• Low-Battery Indicator: Alerts when battery replacement is needed.

4. Setup

4.1 Battery Installation

1. Locate the battery compartment cover on the back of the Phototach unit.
2. Slide or unclip the cover to open.
3. Insert the required batteries (typically AA or 9V, refer to the unit's markings) ensuring correct polarity (+/-).
4. Replace the battery compartment cover securely.

4.2 Preparing for Non-Contact Measurement

For non-contact measurements, reflective tape is required on the target object.

1. Clean the surface of the rotating object where the measurement will be taken.
2. Cut a small piece of the provided reflective tape.
3. Affix the reflective tape to the rotating object. Ensure it is flat and securely attached.
4. The reflective tape should be positioned so that the laser beam can easily target it during rotation.

4.3 Preparing for Contact Measurement

For contact measurements, attach the appropriate contact adapter tip.

1. Select the desired contact adapter tip (e.g., cone for shafts, funnel for concave surfaces, or wheel for linear speed).
2. Clip the chosen adapter tip securely onto the contact adapter shaft of the Phototach.
3. Ensure the adapter is firmly seated to prevent inaccurate readings or detachment during use.

5. Operating Instructions

5.1 Non-Contact Measurement (Phototach Mode)

This mode uses the laser and reflective tape to measure RPM without physical contact.

1. Ensure the reflective tape is applied to the rotating object as described in Section 4.2.
2. Turn on the Phototach unit.
3. Point the laser beam at the reflective tape on the rotating object. The optimal measuring distance is between 2 inches and 20 inches (5 cm to 50 cm).
4. Press and hold the measurement button (often labeled "MEAS" or similar). The display will show the current RPM.
5. Adjust your position slightly if the reading is unstable until a consistent RPM value is displayed.
6. Release the measurement button to hold the last reading. The unit may also store Min/Max values automatically or via a dedicated "MEM" button.

5.2 Contact Measurement

This mode uses physical contact with the rotating object via the adapter tips.

1. Ensure the appropriate contact adapter tip is securely attached as described in Section 4.3.
2. Turn on the Phototach unit.
3. Gently press the contact adapter tip against the center of the rotating shaft or surface. Apply enough pressure to ensure consistent contact without impeding rotation.
4. Press and hold the measurement button. The display will show the current RPM.
5. Maintain steady contact for an accurate reading.
6. Release the measurement button to hold the last reading.

5.3 Memory Function (Min/Max)

The Phototach can store the minimum and maximum RPM values recorded during a measurement session.

• During or after a measurement, press the "MEM" button (if available) to cycle through current, minimum, and maximum readings.
• Consult the device's specific button layout for exact memory recall procedures.

6. Maintenance

6.1 Cleaning

• Wipe the unit with a soft, dry cloth.
• For stubborn dirt, use a slightly damp cloth with mild soap, then wipe dry.
• Do not use abrasive cleaners, solvents, or harsh chemicals, as these can damage the casing or display.
• Keep the laser aperture and sensor lens clean for accurate non-contact measurements. Use a lens cleaning cloth if necessary.

6.2 Storage

• When not in use for extended periods, remove the batteries to prevent leakage.
• Store the Phototach and its accessories in the provided carrying case in a cool, dry place, away from direct sunlight and extreme temperatures.

7. Troubleshooting

8. Specifications

• Model: OTC 3665
• Measurement Range: 2.5 to 99,999 RPM
• Display: 5-digit LCD
• Non-Contact Distance: 2 to 20 inches (5 to 50 cm)
• Accuracy: Typically ±(0.05% + 1 digit) (Note: Specific accuracy may vary, refer to product packaging for precise details.)
• Memory: Minimum and Maximum RPM storage
• Power: (Battery type, e.g., 9V or AA x 4) (Please check your unit for specific battery requirements)
• Dimensions (L x W x H): Approximately 10.45 x 5.95 x 3.15 inches (26.5 x 15.1 x 8.0 cm)
• Weight: Approximately 0.035 ounces (1 gram) (Note: This weight is for the unit itself, excluding packaging and accessories.)
• Material: Plastic, Metal

9. Warranty and Support

For warranty information and technical support, please refer to the official OTC website or contact their customer service department. Keep your purchase receipt as proof of purchase.

OTC Customer Support: Visit OTC Tools Support Page

Note: Warranty terms and conditions may vary by region and retailer.