AR500 Laser Position Sensor

The AR500 is a compact triangulation laser sensor that excels in its versatility. The AR500 is available with measurement ranges from 5mm (0.2 in.) to 1000mm (39.4 in). The red or blue laser is available with an assortment of power options (from Class 2 to 3B) for applications that require a brighter laser. A factory installed internal heater, air jacket, or splash guard is available for challenging environments.

Product ID: 3754 Category:

Many Ranges, Exceptional Accuracy, One Case

The AR500 Triangulation Sensor measures 20 x 61 x 50mm (0.79 x 2.40 x 1.97 in.). It comes in 9 different ranges: 5mm, 10mm, 25mm, 50mm, 100mm, 250mm, 500mm, 750mm, and 1000mm. The AR100 has a 0.1% linearity and 0.01% resolution over the full measurement range for the 5mm to 750mm models, and a 0.15% linearity and 0.02% resolution over the full measurement range for the 1000mm model. The AR500 has a maximum sampling rate of 9.4 kHz, but if you need even more speed, a high-speed version—the AR550—boasts a sampling rate of 70 kHz.

Versatile Laser Diode Options

The AR500 is available with several power options for both red (660 nm) and blue (405 n m) lasers. Depending on the range, you can select between Class 2 (< 1 mW), Class 3R (< 5 mW), and Class 3B (~ 20 mW) lasers in both colors. The higher powers are useful in applications where the target is especially dark and far away, and they can help reduce noise in applications where a Class 2 laser just isn’t bright enough.

(Note: Class 3B lasers require certified eye protection for safe operation. Not all power options are available for all ranges. Speak to your Acuity Sales Representative for more details.)

Freezing, Sweltering, Unusually Wet? There’s an Option for That.

The AR500’s enclosure has a rating of IP67, so it can withstand dusty environments and occasional splashes without any additional options. It has a normal recommended operating temperature range of -10 to 60°C (14 to 140°C), so it can work in most environments without modification.

But if your application doesn’t take place in “most environments,” the AR500 has you covered with these factory-installed options:

  • An internal heater that allows operation in temperatures as low as -30°C (-22°F).
  • An air jacket that allows operation in ambient temperatures as high as 120°C (248°F)
  • A splash shield that helps keep water from landing on the laser window and interfering with the beam or optics.

Outputs and Inputs

The AR500 comes with a standard RS232 or optional RS485 serial interface for communication with a computer or PLC, but if you need the laser to connect directly with a modern PC, an Ethernet output option is available. (Note: A minimum quantity is required for the Ethernet option. Speak to your Acuity Sales Representative for more details.)

The AR500 also comes with an analog output—your choice of 4-20mA or 0-10V. The analog output can be programmed to have a custom measurement range, and the minimum and maximum can be set to any points in the laser’s range.

The AR500 has a limit output for indicating alarms. This can be useful for triggering an external device when a target reaches a set position. The AR500 also has a line in to receive an external trigger to take single distance measurements.

AR500 Case Studies

Crash Test Sensors

Engineers of automobile crash tests use the AR500 laser position sensor to measure the car’s deceleration during the crash event. Analog signals from the sensors are used to produce a deceleration curve plotted against time.

Laser Ride Height Sensor

When it comes to vehicle dynamics, providing precise ride height measurement from the vehicle to the ground is critical for testing different variables under one measurement.

Specifications

See PDF datasheet for full specs

Base Distance: Offset distance from the face of the sensor to the beginning of the measurement edge. Accuracy is greatest at the middle of the range, and the laser spot size is the smallest at the middle of the measurement range.

Range: Working distance between measurement endpoints over which the sensor will reliably measure displacement.

Resolution: Smallest change in distance that a sensor can detect. Stated as % of the full scale range

Linearity: The largest deviation from a best-fit straight line over the measurement range, created by data from the sensor with reference taken from a true distance scale. Stated as ±% of the Range.

Sample Rate: Speed that data samples are obtained from the sensor.

Options and Accessories

Connection Options

Acuity offers the following outputs for the AR500 Compact Triangulation Sensor:

Serial Outputs (Choose One)

RS-232

An RS-232 0utput is standard on the AR500. Cables purchased with the laser come with flying leads that can be wired directly to whatever connector your computer or PLC uses. The data from the AR500 can be set to binary or ASCII output. The maximum transfer rate is 921600 baud.

RS-485

The AR500 can be purchased with an RS-485 serial output for applications that require long cables (> 20 ft). The RS-485 serial output replaces the RS-232 output, so please double check the output your application requires before ordering. The available sample rates, formats and software configuration commands are the same for a RS-485 output as it is for RS-232.

Analog Outputs (Choose One)

4-20 mA

A 4-20 mA analog output is preferred when there is a possibility of interference as the signal travels through the cable. The maximum and minimum current outputs can be set to any point on the sensor’s range, even inverting direction if necessary. We suggest that a 400 to 500 Ω resistor be connected to the current loop wires at the measurement point for best accuracy.

0-10 V

Some PLCs require a 0-10V analog output. Like with the 4-20mA output, the maximum and minimum current outputs can be set to any point on the sensor’s range, even inverting direction if necessary. We do recommend using the shortest length of cable feasible to reduce any noise causing interference.

Ethernet (Minimum Quantity Required)

An Ethernet connection option is available for direct connections to modern PCs. A minimum quantity is required. Speak to your Acuity Sales Representative for more details.

Environmental Endurance Options

Internal Heater

The AR500 can be ordered with a factory installed, internal heater. This heater allows the sensor to be operated in temperatures down to -30°C (-22°F). This allows the AR500 to be installed in cold environments without a custom-built enclosure. Users can configure the temperature settings to suit their application.

Air Jacket

The AR500 can also be ordered with a factory installed, air jacket. With appropriate forced air applied, the air jacket allows the AR500 to operate in ambient temperatures as high as 120°C (248°F). This allows the AR500 to be installed in hot environments without a custom-built enclosure.

Splash Guard

The AR500 is available with a factory installed splash guard. This doesn’t improve the laser’s resistance to water (the AR500 is rated as IP67 and can withstand splashes), but it does help keep the laser window free of water, dirt, oil, and other debris and reduces the need to clean the window to ensure accurate operation.

Display Accessories

Touch Panel Display
Touch Panel Display with data display

The Acuity Touch Panel Display is a stand-alone terminal interface for use with Acuity laser distance sensors. These fully enclosed units replace panel meters, alphanumeric displays, and analog controllers by providing a modern interface through a full-color LCD and touch screen. The Touch Panel Display communicates with one or two Acuity sensors using RS-232 serial interfaces. The touch panel can be easily configured using on-screen buttons to display, scale, and even graph the sensors’ distance outputs. Relative dimensions can be measured using a tare function. With two Acuity sensors, the touch panel can serve as a thickness gauge. Limits can be programmed into the touch panel to give a visual warning to operators that the target is too close or too far or too thick or too thin. With a USB flash drive, measurements can be logged and saved for further analysis.

Connection Accessories

Connectivity Kit
Connectivity Kit

The AR500 laser measurement sensor comes with an unterminated bundle of wires in a shielded cable. As an option, Acuity sells a connectivity kit to aid in connecting your laser to a power supply and serial port. This product includes a 120V, 15 VDC, AC power supply; a serial cable with DB9 connector; and a solid-state, NEMA-4X interface box. The interface box includes two sets of terminal blocks for simple input (from sensor) and output (to your selected device), a DB9 male serial connector out, and a barrel style power connector in. You can either pass through the wiring to another unterminated cable, connect a DB9 serial cable directly to the interface box, or both at the same time.

Also available: Serial to USB cable option; 240 V version with a European-style plug.

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