User Guide
Panel Mount Digital Tachometer
Model 461950
Introduction
Congratulations on your purchase of the Extech 461950 Panel Tachometer. This meter
displays continuous readings from 5 to 99,990 rpm. Single pulse activation eliminates the
need for special gears when setting up the meter in any given application. Models 461955
(proximity sensor) and 461957 (photoelectric sensor) are also covered in this manual.
Careful use of these devices will provide years of reliable service.
Specifications
Model 461950 Panel Tachometer
Range
Resolution
Accuracy
Display
Display update rate
Power
Panel cutout dimensions
Bezel dimensions
Meter dimensions/Weight
5 to 99,990 RPM
0.1 (5 to 999.9); 1 (1000 to 9999); 10 (10.000 to 99,990)
0.05% + digit (of reading)
0.5 " (13mm) 4-digit (9999 count) LED display
Once per second
110/220VAC; 50/60Hz ±15%
3.62 x 1.77" (92 x 45mm)
3.78 x 1.89 x 2.36" (96 x 48 x 60mm)
3.61 x 1.66 x 3.54" (92 x 42 x 90mm); 13.9 oz. (397 g)
Model 461957 Photoelectric Sensor
Range
Power
Response time
Output
Photo beam color
Photo beam wavelength
Cable length
Up to 6000 RPM (100 Hz)
12 - 24VDC ±10%; Consumption: 40mA max.
< 1ms
NPN transistor; Max load 80mA
Green
5500 Angstroms
6 ft (1.8 meters)
Model 461955 Proximity Switch
Range
Power
Power Consumption
Object distance detection
Object size detection
Cable length
Up to 36,000 RPM (600 Hz)
12 – 24VDC ±10%
10mA max.
0.1" (3 mm) maximum target distance
0.07 x 0.11" (2 x 3 mm) minimum size detected
6 ft (1.8meters)
2
Model 461950 Version 1.7 May 2004
Mounting Instructions
Panel Meter Mounting
1.
The 461950 dimensions are:
Meter: 3.61 x 1.66 x 3.54 " (92 x 42 x 90 mm)
Bezel: 3.78 x 1.89 x 2.36 " (96 x 48 x 60 mm)
2.
3.
Prepare a panel cutout with the following dimensions: 3.62 x 1.77" (92 x 45 mm).
The Tachometer will fit a standard 1/8 DIN cutout. Mounting hardware is provided
which attaches to the sides of the meter. The screws attached to the mounting
bracket should be tightened to the back of the panel (avoid over-tightening which can
bow the meter housing).
Proximity Switch Model 461955 Mounting
Use the mounting holes to secure the proximity switch to the desired surface. The sensor
is the side of the switch that detects a moving metal object such as a gear tooth or a fan
blade. The sensor side of the switch has an X on it and is located on the opposite side of
the switch from the wiring cable. Refer to the top view diagram below. The Proximity switch
must be mounted so that the object being detected passes within 0.16" (4mm) of the
sensor side of the switch. The pulse LED will light when the sensor detects a metal object.
Wiring Cable
Pulse LED
Sensor
Mounting Holes
Photoelectric Sensor Model 461957 Mounting
Use the mounting holes to secure the photoelectric sensor to the desired surface. The
photo beam is generated and detected in the groove (as depicted by the dotted line in the
diagram below). The object under test must pass in the groove so that the light beam can
be interrupted.
Sensor groove
Power and
Detection LEDs
Sensitivity
adjustment screw
Mounting holes
3
Model 461950 Version 1.7 May 2004
Wiring Instructions
The Model 461950 has seven screw terminals for AC power, sensor input, and sensor
excitation.
Model 461955 Proximity Switch Wiring
1.
2.
3.
Brown wire (10 - 30V supply signal) to terminal 3 on the panel tachometer (+12V)
Black wire to terminal 2
Blue wire to terminal 1
Model 461957 Photoelectric Sensor Wiring
1. Brown wire connects to terminal 3 of the panel tachometer
2. Blue wire connects to terminal 1
3. Black wire (sensor output during high to low transition) or Green wire (sensor output
during low to high transition) connects to terminal 2. Connect one wire only to terminal
2 (black or green) depending upon which better suits the application.
AC Power Wiring
Meter terminals 5, 6, and 7, are for AC power connections. Connect to terminals 5 and 7
for 220V applications. Connect to terminals 6 and 7 for 110V power applications. A
Wiring Diagram
Model 461950 Panel Tachometer
Sensor Input
GND POS +12
NC
AC Power
220V 110V
Neutral
1
2
3
4
5
6
7
NOTE:
Fusing and electrical noise preventative devices such as MOVS, RC networks, and
line filters should be considered by the user when installing to avoid electrical noise
interference.
4
Model 461950 Version 1.7 May 2004
Meter and Sensor Operation
Meter Operation
Mount and wire the meter as previously described. The Model 461950 Panel Mount
Tachometer was designed to measure and display RPM in the following ranges:
Ranges
5 – 999.9 rpm
1000 - 9999 rpm
10,000 - 99,990 rpm
Resolution
0.1 rpm
1 rpm
10 rpm
Accuracy (of rdg)
±(0.05% + 1 digit)
Extech sensors generate pulses that are counted by the meter and converted to RPM. The
meter computes RPM values based on the number of pulses detected in a given period of
time and provides an RPM display on the 4 digit (9999 count) LED.
Operation of the Proximity Switch Model 491955
The Extech
Proximity Switch
Model 461955 connects directly to the tachometer's input
terminals and measures up to 36,000 RPM (600 Hz). Proximity switches detect magnetic
(ferrous) objects as they pass the sensor, sending a pulse, one for each pass, to the
meter. The pulse LED on the switch lights with each pass. The meter then calculates RPM
and updates the LED display.
Operation of the Photoelectric Sensor Model 461957
Extech
Photoelectric Sensor
Model 461957 connects directly to the tachometer's input
terminals and measures up to 6,000 RPM (100Hz). When the sensor is properly powered
(by the voltage on terminal 3 of the meter), the green power LED (on the sensor) will
switch on.
Photoelectric sensors generate a light beam that is interrupted by an object as it passes
through the beam. Each time the beam of light is interrupted a pulse is transmitted to the
meter and the red status LED on the sensor blinks. The meter then calculates and displays
the RPM based on the number of pulses received in a specific period of time.
The sensitivity adjustment screw on the sensor may have to be adjusted so that one pulse
is generated for each interruption of the light beam. If the red LED turns on less/more than
once for each interruption of the beam, adjust the sensitivity screw.
5
Model 461950 Version 1.7 May 2004
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
