What is ALHS?
Automatic Load Height Sensor, also known as ALHS has many benefits when installed to your Eagle series stretch wrapper. One is to identify the top of the pallet load that our Eagle series stretch wrappers are equipped with. And two, it will determine when a load has been placed on the your machine. There are several types of load height sensors. For example we have listed two of our common sensors below.
Diffused Light Sensors
A diffused light sensor is commonly called as proximity mode. When light strikes the target from various angels it becomes diffused. After light returns directly to the receiver the target has been detected. Factors such as color, size and finish determine the target. The actual sensing range for each model is based upon a “white card test”. The white card has a 90% reflectivity factor and is considered a “standard target”. Targets with darker colored or a matte finish provides less reflectivity. In other words, increase the sensitivity or position the sensor closer to the target.
- Diffused with background suppression
- Sensors with background suppression have a defined sensing range for any object regardless of color, reflectivity or finish. These sensors are easy to install and adjust. As well as detect dark objects placed on shiny backgrounds.
- Diffused with foreground suppression
- Sensors with foreground suppression define a “dead-band” from the sensor’s optical window. Objects that fall inside this minimum sensing distance are ignored.
- Diffused with background evaluation
- Sensors with background evaluation only evaluate the light reflected by the background (i.e. the floor). If the sensor is not able to see the background, the output will change state. This is useful in applications with odd shapes where direct light at the target cannot be reflected back to the sensors.
Digital laser load height sensor
A laser load height sensor enables long distance detection. This is useful for difficult applications where there must be a focused, visible beam spot. TOF (Time of Flight) is the method used to measure distance using a laser.
The TOF method of detection measures distance by calculating the time it takes for a pulse-emitted beam to leave the sensor, hit the target, and then return to the sensor. Therefore this provides stability of the detected work piece.
Eagle Stretch Wrappers
Eagle stretch wrapping machines feature load height sensors. Click here to view more information on our stretch wrapping machines.
Need further assistance with your Eagle stretch wrapper? We also sell Eagle stretch wrapping supplies. Give us a call anytime between 8:00am and 4:00pm Monday through Friday and a member of our sales team will be happy to assist you.