Extech 461891 High Precision Contact Tachometer

This instrument allows you to directly measure the rotational speed of shafts or spindles by placing the contact tip on the rotating part, or by using the supplied wheels/adapters to measure surface speeds (in ft/min or m/min) by rolling the wheel on the moving surface. It is autoranging, has a large 5-digit LCD display for clear readings, and memory capabilities (recalling last, max, and min measured values). Typical RPM range goes from about 0.5 up to nearly 20,000 rpm, and surface speed ranges go from very low (0.2 ft/min or 0.05 m/min) up to high values (6,560 ft/min or ~2,000 m/min) depending on the wheel used. 
The device is powered by AA batteries, supplied with accessories including a cone tip, flat tip, surface-wheel adapter, spare wheel, carrying case, and user manual—making it field-ready out of the box. 
It is suitable for industrial maintenance, manufacturing, and diagnostic work where precise speed measurement of rotating machinery is critical.

Features

• Contact measurement range: approx. 0.5 to 19,999 rpm for rotating objects.

• Surface speed measurement range: ~0.2 to 6,560 ft/min (0.05 to ~1,999.9 m/min) using accessory wheels.

• High accuracy: basic accuracy rated at about ±(0.05% of reading + 1 digit) for RPM measurement.

• Large 5-digit LCD display for clear resolution and readability.

• Memory functionality: retains last reading and can recall Minimum and Maximum readings recorded.

• Autoranging from low to high speeds, making it versatile for both slow and fast rotating applications.

• Supplied contact tips (cone and flat) and surface-speed wheels included for measuring different types of surfaces and shafts.

• Portable, handheld form factor with battery power (4 × AA), ideal for field use and maintenance work.

Includes

• Four AA batteries
• Carrying case
• User manual