RETAINER 6A4443 - Caterpillar

Introduction
The 1U6602 Photo-Tach (Tachometer) Group provides a safe, accurate, digital, noncontact method for measurement of rotational speed. It measures rpm by directing an integral light source onto a piece of reflective tape. The photo-tach can be used to measure the rotational speed of any part, where a piece of reflective tape can be positioned. During use the photo-tach will count the reflected light pulses.To use the 1U7771 Photo-Tach, aim it at the reflective tape (target), squeeze and hold the trigger on the pistol grip and read the speed. The last reading is displayed for about one minute after release of the trigger. If the trigger is squeezed again, new measurements begin immediately.The rpm is directly displayed on a liquid crystal digital (LCD) four and one-half digit display in numbers 10.2 mm (0.4") high. The 1U7771 Photo-Tach provides the noncontact measurement of rotational speed for a range of 50 to 20,000 rpm, with an accuracy of 1 rpm.Components of 1U6602 Photo-Tach Group
(1) 6V3073 Case. (2) 1U7772 Foam Block. (3) 1U7771 Photo-Tach. (4) Batteries. (5) 1U6605 Reflective Tape.
Optional Items:
(6) 1U6603 110/220 VAC Recharger. (7) 1U7445 Nickel Cadmium Batteries (not shown) - 4 required.Specifications for 1U6602 Photo-Tach Group
MEASUREMENT RANGE: 50 rpm to 20,000 rpm. ACCURACY: 1 rpm. RESOLUTION: 1 rpm. DISPLAY: 4 1/2 digit, 10.2 mm (0.4") high liquid crystal. ON TARGET INDICATION: Steady illumination of the plus sign. OPERATING ENVELOPE: Range: 0 to 0.92 m (0 to 3') from reflective tape. Angle: Up to 45 degrees from perpendicular to reflective target. LAST MEASUREMENT MEMORY: Displays last measurement approximately one minute after trigger release. POWER ON SWITCH: Pistol grip trigger may be locked on with latching push button for longer duration measurements. OPTICAL SYSTEM: Single lens reflex. Visible light source. TIME BASE: Crystal controlled. POWER SOURCE: Four "AA" batteries. Recharger socket provided for optional rechargeable batteries. SIZE: 83 mm x 45 mm x 156 mm (3.25" x 1.75" x 6.13"). WEIGHT: Approximately 0.57 kg (1.25 lbs).Operation
The 1U7771 Photo-Tach measures rotational speed from a single pulse per revolution. This pulse is supplied by attaching a piece of 1U6605 Reflective Tape to the rotating part, in an easily accessible location. The 1U7771 Photo-Tach is equipped with a built-in steady state DC light source. This light source provides a light beam that is aimed at the reflective tape target on the rotating part. A target about 12.7 mm (0.5") square, or larger, is recommended for normal operation.The light pulse that is reflected from the rotating part is received back through a single lens reflex optical system, and read by a photo cell inside the photo-tach. The plus (+) sign on the left side of the display, provides an "on target" indicator to verify that the photo-tach is on target, and is receiving valid information. The photo-tach then computes the rotational speed, and displays it to a resolution of 1 rpm.To use the photo-tach, aim it at the reflective tape while holding it at a distance of 25.4 mm (1.00") to 0.92 m