Why is a laser sensor good for precise measurements?

Have you ever visited an electronics plant or observed production of automotive components? Precision is vital in these contexts. A mistake of only a few tenths of a millimeter, for example, could render an entire assembly inoperable. Laser sensors have become quite popular for precise measurements in many industries. But, what makes laser sensors so accurate? Certainly, other industries, besides electronics, depend on laser sensors, such as automobile, aerospace, and other high precision engineering sectors. Let's consider how laser sensors become invaluable precision measurement tools laser sensor features, and actual production work.

Fundamentals of Laser Light Technology

To begin with, the laser sensor requires a laser, and that's where the precision comes in—laser light isn't the same as the light from a light bulb or an LED. Ordinary light spreads wide and diffuse. For example, a person shining a flashlight across a room, the beam of light will spread and get larger and dimmer the farther from the light source. Laser light, on the other hand, is monochromatic and collimated. That means, the beam is of one wavelength, essentially one color, and does not spread and lose focus over distance. That is a significant advantage in measurement.

When a laser sensor is used, it sends a focused beam of light to the object being measured. This means the beam will accurately hit the measuring point, and there will be no spread or "blurriness" in the measurement. For example, in a smartphone factory, workers need to check if the glass screen is perfectly aligned with the phone's body. A laser sensor can accurately measure the distance to a point on the glass screen edge, and determine the gap between the screen and body to 0.001mm. In comparison, ordinary sensors, such as some photoelectric ones, would have a wider beam that covers both the screen and body, and resort to an approximate vague reading.

LUOSHIDA specializes in sensors, and when designing laser sensors, they always keep this in mind. For example, in their LCD-XXYYYAB series, they claim to provide a focused laser beam for detection at distances ranging from 30 to 100 mm (and in some models, even further is marked with "M"). Depending on the model, the beam diameter is adjustable from 3 mm to 50 mm. This means centered and focused detection on small parts even at a distance. This focus means every measurement is based on the exact spot you care about, and not a broad area that might include irrelevant details.

Another thing about laser light, and this is crucial in a positive sense, is that it is consistent. The sensors can determine distance and size based on how the laser beam returns after hitting the targeted object (this is time-of-flight and triangulation measuring methods). There will be no guesswork when it comes to stating the distance and size. If the laser wavelength changed, the sensors would determine the distance with confusion. Stable laser means every bounce returns consistent value, which is vital in measuring a car part's metal sheet. If it is measuring 0.01 mm and is too thin, it can jeopardize the strength of the part.

Resistance to Outside Disturbance

*A measuring tool's effectiveness relies not only on its own construction but how well it performs under dirty, real-world conditions. Fab plants are cluttered with things that can disrupt sensors—lights, dust, vibrations, and even the electromagnetic fields generated by welding tools and other heavy machinery. However, laser sensors address these problems and continue to give accurate measurements even in tough circumstances.*

*When it comes to light disturbance, standard photoelectric sensors can get perplexed in a laser factory with overhead lights or sunlight coming through the windows. Regular sensors can confuse ambient light with the sensor's output signal and produce inaccurate measurements. However, laser sensors emit a light beam of a special wavelength and are equipped with filters to block other light. Such sensors can work in fully illuminated factories, "seeing" only the beam of laser light and "ignoring" all other ambient lights. For instance, in solar panel factories, workers measure the thickness of silicon wafers under powerful overhead lights. Laser sensors can "ignore" extra light and accurately measure the thickness of the wafer, which is a 0.2mm thick wafer, even under extreme conditions.*

Lastly, consider electromagnetic interference (EMI), which is the "noise" produced by machines like motors and welding equipment. EMI is like static interference on a radio when you stand close to a large appliance. EMI is also produced by machines with many internal circuits, and it disrupts their readings. Laser sensors, like those from LUOSHIDA, undergo rigorous testing to ensure compliance with EMI standards such as EN 61000-6-3:2007+A1:2011 and EN 61000-6-1:2007. This means that the sensors have EMI shielding. In the automotive industry, welding robots generate strong EMI but the laser sensors are still able to accurately measure the gap between two welded parts without generating false readings and allowing the production line to run uninterrupted.

Dust and moisture are also significant concerns. In woodworking and metal-cutting shops, dust is pervasive and can cover regular sensors. However, many laser sensors have protective enclosures, and some come with durable designs that boast IP67 or higher ratings. In a dusty lathe processing area, where metal shavings are flying, it is important to have laser sensors to ensure that their lens remains clear and their measurements are accurate.

Adaptability to Varied Laser Measurement Needs

Unlike many other measurement tools, laser sensors can be fine-tuned and tailored to meet specific needs and measurement tasks. This is very important for businesses that deal with a wide range of components. These include small electronic devices and large metal parts. Laser sensors can measure distance, thickness, alignment, and even surface texture with the same precision.

Take the electronics industry for example. While assembling a laptop, workers have to position small components (like resistors, which are smaller than a grain of rice) on the circuit board. A laser sensor can measure the height of the component post placement. If the component is above a certain height, that means it isn't soldered correctly. This type of laser sensor can measure the distance between the laptop's keyboard and screen later in production to ensure they close correctly. LUOSHIDA laser sensors are adjustable detection ranges (from 30mm to 100M, depending on the model) and different output functions (NPN, PNP, AC, or AC/DC Relay) which allows them to be customized for different functions.

Another industry that requires precision is medical devices. The manufacturing of surgical tools and insulin pumps entails such remarkable precision that a mistake of the width of a hair (~0.05mm) is unacceptable. Laser sensors check that the diameter of syringes and needles is 0.3mm, and that it is not less or more. The manufacturing of medical devices requires clean environments, and the small size of laser sensors (most are round or square and easy to fit into small clean rooms) is beneficial.

Even precision agriculture needs to be incorporated. For example, at automated seed planter manufacturing facilities, laser sensors check to ensure seed planter holes are just the right size, not too large (to prevent seeds from falling out) and not too small (to prevent seed from getting stuck). Chenwei Automation, a distributor of LUOSHIDA sensors, collaborates with clients to customize laser sensors for such applications, such as seed size focusing. This means that a single laser sensor, perfectly tuned, is capable of performing numerous laser measurement tasks with precision. Other sensors do not have to be adapted for different applications.

Reliable Quality Ensures Sanity in Consistent Precision Over Time

Having precision many not necessary mean that you are required to have one good reading, but one accurate reading at a laser sensor remains not easy to maintain it over a long period of time in extensive periods. This is because, in comparing to more advanced and more expensive laser sensors, cheap sensors are meant to last not more than a week in optimal functionality, after which their precision measuring turns to inconsistency, and all it takes is a dimmed laser, and/or worn out circuits.

LUOSHIDA has been certified under ISO 9001:2015 to have a complete and consistent quality in all certified realms of LASER, sensor and sensor assembly production. Sensors not having damaging substances are of more consistent value and quality of certified circuitry to maintain sensors not having lead that causes corroding circuits and drifting precision ability and sensors not having lead in circuits and therefore corroding over time will not precision drift off setting.

Let's talk about warranties and support. Most laser sensors come with warranties for about two years, and LUOSHIDA is one of these. This signifies that they trust the accuracy of their products. Should one of the sensors start malfunctioning during that time, they will repair or replace it entirely for free. This becomes critical for industries that are on 24/7 operations like semiconductor factories. You will not be able to halt production to correct a loss of precision on a sensor and a solid warranty means that there are a set of sensors waiting on the shelf as a backup.

The durability of laser sensors is also a crucial factor. These sensors can be encased in robust materials like aluminum or have internal components that can withstand extreme temperatures (80°C and over). In a reflow machine used for electronics, a sensor can stay very close to the machine and not lose its precision as it measures circuit boards. Unlike regular sensors that will melt and lose calibration in extreme heat, durable laser sensors keep working and do their job of measuring.

Over time, reliability pays off. A LUOSHIDA laser sensor that users say remains precise for 3-5 years means never needing time every week for recalibration. No need to sensor replacement every couple months also cheapens downtime. This consistency means sameness in every product made, high precision standards. There will be no more "good batches" and "bad batches" because of a sensor's inconsistency.