Introduction
The BAFX Products Contact Tachometer, Model BAFX1735, is a handheld device designed for accurate measurement of rotational and linear speeds. This instrument provides precise readings in Revolutions Per Minute (RPM), feet per minute (ft/min), or meters per minute (m/min), making it suitable for a wide range of industrial, automotive, and hobbyist applications. This manual provides detailed instructions for the proper setup, operation, and maintenance of your tachometer.
Package Contents
Please verify that all items listed below are included in your package:
- 1x BAFX Products Contact Tachometer Unit
- 1x 1/2" RPM Adapter (Cone-shaped)
- 1x 1/4" RPM Adapter (Cone-shaped)
- 1x 1/4" Shaft Adapter (Cylindrical)
- 1x Linear Speed Wheel with 1/8" Cable Slot
- 1x Adapter Connector
- 2x AAA Batteries


Features
- Versatile Measurement: Capable of measuring both rotational (RPM) and linear speeds (ft/min, m/min).
- Wide Measuring Range: 0.5 to 19,999 RPM.
- High Precision: Accuracy of +/- 0.5% + 1 digit.
- Multiple Adapters: Includes 1/2" RPM adapter, 1/4" RPM adapter, 1/4" shaft adapter, and a linear speed wheel with a 1/8" cable slot for diverse applications.
- Data Hold Functions: Features MAX (maximum), MIN (minimum), LAST (last reading), and AVERAGE reading functions for comprehensive analysis.
- Portable Design: Compact and handheld for ease of use in various environments.
- Battery Operated: Powered by 2x AAA batteries (included).

Setup
1. Battery Installation
- Locate the battery compartment cover on the back of the tachometer unit.
- Slide the cover open or remove it according to the markings.
- Insert two (2) AAA batteries, ensuring correct polarity (+/-) as indicated inside the compartment.
- Replace the battery compartment cover securely.

2. Attaching Adapters
Select the appropriate adapter for your measurement task:
- For Rotational Speed (RPM): Use either the 1/2" RPM adapter, 1/4" RPM adapter, or 1/4" shaft adapter. These adapters are designed to make contact with the rotating object.
- For Linear Speed (ft/min, m/min): Use the linear speed wheel. This wheel is designed to roll along a moving surface or can be used with its 1/8" slot for wires/ropes.
To attach an adapter, firmly push it onto the metal shaft at the top of the tachometer unit. Ensure the adapter is seated securely to prevent it from detaching during operation. If an adapter feels loose, ensure it is fully pushed onto the shaft. The adapter connector may be used to extend the reach or provide a more stable connection for certain adapters.
Operating Instructions
1. Powering On/Off
Press the Power button (usually marked with a power symbol) to turn the tachometer on. Press and hold the Power button again to turn it off.
2. Taking Measurements
- Ensure the correct adapter is securely attached for your desired measurement type.
- Turn on the tachometer. The display will show '0.0' or the last reading.
- For Rotational Speed: Gently press the tip of the cone adapter or the shaft adapter against the center of the rotating object (e.g., shaft, flywheel). Maintain steady contact. The display will show the RPM reading.
- For Linear Speed: Press the linear speed wheel against the moving surface (e.g., conveyor belt, wheel circumference) or insert a wire/rope into the 1/8" slot. Maintain steady contact. The display will show the linear speed in ft/min or m/min.
- The tachometer will continuously update the reading as long as contact is maintained.
3. Using Data Hold Functions (MAX/MIN/LAST/AVERAGE)
During or after a measurement session, you can access stored data:
- Press the MEM button (Memory) to cycle through the stored values.
- The display will show:
- MAX: The highest speed recorded during the current measurement session.
- MIN: The lowest speed recorded during the current measurement session.
- LAST: The most recent stable reading taken.
- AVG: The average speed calculated from the measurement session.
- To clear the stored data and start a new session, turn the device off and then on again.
Maintenance
- Cleaning: Wipe the tachometer and its adapters with a soft, dry cloth. Do not use abrasive cleaners or solvents.
- Battery Replacement: Replace batteries when the low battery indicator appears on the display to ensure accurate readings. Refer to the "Battery Installation" section for instructions.
- Storage: Store the tachometer and its accessories in a dry, cool place, away from direct sunlight and extreme temperatures. Remove batteries if the device will not be used for an extended period to prevent leakage.
- Adapter Care: Inspect adapters for wear or damage before each use. Ensure they are clean and free of debris that could affect contact or accuracy.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Tachometer does not power on. | Dead or incorrectly installed batteries. | Check battery polarity. Replace with fresh AAA batteries. |
| Inaccurate or unstable readings. | Poor contact with the object; incorrect adapter; object not rotating smoothly; low battery. | Ensure firm, steady contact. Use the correct adapter for the measurement type. Check for smooth rotation of the object. Replace batteries. |
| Adapter detaches or feels loose during use. | Adapter not fully seated on the shaft; worn adapter. | Push the adapter firmly onto the metal shaft until it is secure. If the adapter is worn, consider replacing it. |
| Display shows 'OL' or 'Err'. | Measurement range exceeded; sensor error. | Ensure the speed of the object is within the tachometer's specified range (0.5~19,999 RPM). Turn off and restart the device. |
Specifications
| Parameter | Value |
|---|---|
| Measuring Range | 0.5 ~ 19,999 RPM |
| Resolution | 0.1 (0.5 ~ 999.9 RPM) 1.0 (1,000 ~ 19,999 RPM) |
| Precision | +/- 0.5% + 1 digit |
| Sample Interval | 1x / 0.8s (Over 60 RPM) |
| Power Supply | 2x 1.5V AAA Batteries |
| Item Weight | 150 g (approx. 5.3 ounces) |
| Parcel Dimensions | 17.6 x 12.5 x 5.59 cm |
| Material | Metal (shaft), Plastic (housing, adapters) |
| Model Number | BAFX1735 |

Warranty and Support
This BAFX Products Contact Tachometer (Model BAFX1735) comes with a 1-Year Manufacturer Warranty against all manufacturing defects. For warranty claims, technical assistance, or any product-related inquiries, please contact BAFX Products customer support. Support is based in the USA.
Please retain your proof of purchase for warranty validation.