The Murphy 4000 RPM Alternator Signal Tachometer/Hourmeter 11-28 VDC with Bright Stainless Steel Bezel ATHA-40 is a rugged, transistorized instrument with solid-state circuitry for indication of engine RPM. It is equipped with a bracket for mounting into a standard 3-3/8" (86 mm) dash mounting hole. A full 270° sweep of the pointer gives an accurate indication on a large easy–to–read scale and the dial can be illuminated for night reading.
This ATHA-40 is designed to function from pulses generated by an alternator with 4, 8, 12, 14, or 16 poles on the rotor. This model is for negative ground, positive ground or isolated electrical systems and are protected against reverse polarity hookup. Powered by a 11-28 VDC battery and are reverse polarity protected.
This part replaces the ATHA-40-12.
- 4000 RPM – 0 to 100,000 hours
- Sensing from Alternator Signal
- High Visibility Analog Readout
- Air Core Movement
- Easy Calibration through Dip Switches
- Through Dial Lighting
- Part No.: ATHA-40
- Scale: 0 - 4000 RPM
- Case Material: Plastic
- Hourmeter Range: 99999.9 hours in 0.1 increments
- Power Input: 11-28VDC (70mA-120mA except lamp load)
- Backlight: 3.4W T-10 wedge base bulb
- RPM Input Signal Voltage: V low: 0.5V max, V high: 8.0V min.
- Accuracy: Tachometer: +2% full scale; Hourmeter: +0.01% hours, +1 count
- Temperature Range: -40oC to +82oC (no permanent damage shall occur)
- Dial (Face Plate): 270° sweep with white numerals (over black background)
- Bezel: 304 Bright Stainless Steel Bezel