Photoelectric Sensor

A: Places where through-beam photoelectric sensors should be avoided

1. Places with a lot of dust;

2. Places with a lot of corrosive gases;

3. Places where water, oil, and chemicals may splash directly;

4. Places where there is direct strong light such as outdoor or sunlight without shading measures.

Places where the ambient temperature changes beyond the specified range of the product; places with large vibration and impact, but no shockproof measures are taken. Precautions for the use of photoelectric sensor switch

1. Avoid strong light sources photoelectric switch sensors can generally work stably when the ambient illumination is high. However, avoid facing the sensor's optical axis directly to strong light sources such as sunlight and incandescent lamps. When the angle between the optical axis of the sensor (receiver) and the strong light source cannot be changed, a shading plate or a shading tube can be installed around the sensor.

2. Prevent mutual interference Photoelectric beam sensors usually have the function of automatically preventing mutual interference, so there is no need to worry about mutual interference. However, when several groups of through-beam infrared photoelectric sensors are installed in parallel and close to each other, adjacent groups and mutual interference should be prevented. The most effective way to prevent this interference is to cross-set the projector and the receiver and to open the group distance when there are more than 2 groups. Of course, using models with different frequencies is also a good way.

3. Mirror angle effect When the object to be measured is shiny or encounters a smooth metal surface, the reflectivity is generally very high, which has a mirror-like effect. At this time, the projector and the detected object should be installed at an angle of 10 to 20 degrees so that its optical axis is not perpendicular to the object to be detected, thereby preventing false operation.

4. Eliminate the influence of background objects When using a reflective diffusion projector and receiver, sometimes the photo reflective sensor may not be able to detect stably because the detected object is close to the background object, or the proximity photo sensor or the background is a smooth object with high reflectivity. Therefore, you can use a distance-limited projector and receiver instead, or use methods such as moving away from the background, removing the background object, painting the background object matte black, or trying to make the background object rough and dark to eliminate it.

A: Checking objects on a production line or conveyor: Photoelectric sensors can detect the size of items to find any errors, or simply find their absence, as well as pick up problems such as misaligned caps on bottles. They are widely used in the food and pharmaceutical industries and packaging plants.

A: It has a longer life, a long sensing range, and is very reliable. Its response time is very fast, and it costs less.

A: Photoelectric sensors mainly consist of a transmitter that emits light and a receiver that receives light. When the emitted light is interrupted or reflected by the sensing object, it changes the amount of light reaching the receiver. The receiver detects this change and converts it into an electrical output.

A: Photoelectric sensors emit a beam of light (visible or infrared) from their light-emitting element. Reflective photoelectric sensors are used to detect beams reflected from a target. Through-beam sensors are used to measure the change in the amount of light caused by the target crossing the optical axis.

A: Basically, a photo-electric sensor has two main components. They are the transmitter (light source) and the receiver (sensor).

A: A optical sensor consists of a light source, a light receiver, a main circuit and an output circuit, and each part has the following functions. The photodiode and phototransistor of the light receiver receive the light emitted from the light source and convert it into an electrical signal.

A: The easiest way to determine how a photoelectric tube works is to connect a multimeter in resistance measurement mode to the two leads and see how the resistance changes when you cover the sensor with your hand, turn off the light, etc. Because the resistance changes a lot, an automatic range meter works well here.

A: The following situations may cause the output signal of the photo electric sensor to be unstable when detecting objects:

①Abnormal power supply;

②Detection frequency is too fast;

③Size problem of the object to be measured;

④The object to be measured is not within the stable detection area of ​​the sensor;

⑤Electrical interference.

Countermeasures:

①Supply a stable voltage to the sensor, and the supplied current must be greater than the current consumption of the sensor.

②The speed at which the object to be measured passes must be slower than the response speed of the sensor;

③The size of the object to be measured must be larger than the standard detection object or the minimum detection object;

④The object to be measured must be detected within the stable detection range of the sensor;

⑤Corresponding protective measures can be taken, such as: making a shielding cover around the probe, grounding the high-power equipment, etc.