What Is an Ultraviolet (UV) Sensor?
Ultraviolet (UV) sensors are sensors that detect ultraviolet light.
UV light is considered as being good for health when exposed to it in moderation and is used for health applications. Also, since ultraviolet rays have a sterilizing effect, sterilization equipment is one of the applications for ultraviolet rays.
However, since ultraviolet rays cannot be seen by the human eye, ultraviolet (UV) sensors are used in UV irradiation devices. In recent years, the sterilizing effects of UV light and UV-curing resins have been attracting attention, and UV irradiation devices are increasingly being used not only in industry but also in the home. There are various types of ultraviolet (UV) sensors in use, with some models outputting intensity and total amount.
Uses of Ultraviolet (UV) Sensors
Devices that artificially irradiate ultraviolet light are used in a variety of applications, from small health devices to industrial applications. Such devices are always equipped with ultraviolet (UV) sensors.
The purpose is to control the intensity of ultraviolet rays, as over-exposure to ultraviolet rays is harmful to the human body.
Industrial applications include the following uses:
- Production of UV-curing resins
- Inside semiconductor manufacturing equipment
- Identification and printing of banknotes
- Tanning salon machines
- Athlete’s foot treatment equipment for the sterilizing effect of
- Ultraviolet light
- Air purifier
Principle of Ultraviolet (UV) Sensors
The main component of a UV sensor is a UV silicon photodiode. When the photodiode is irradiated with light containing ultraviolet rays, an electric current flows. Since the current value changes in accordance with the intensity of the ultraviolet light, the amount of ultraviolet light is detected by measuring the current value.
Photodiodes are characterized by different response speeds, etc., depending on their structure. There are Schottky junction, PN junction, and photoconductive types, each of which has its own characteristics, so they are selected according to the application.
Since diodes do not respond to sunlight, or incandescent light, sensors with optical filters are sold. There are also sensors that detect ultraviolet (UV) light by subtracting the visible light component from the difference between a high-sensitivity and a low-sensitivity Ultraviolet (UV) Sensor.
Some sensors use a photomultiplier tube instead of a photodiode as the UV light receiving element.
Other Information on Ultraviolet (UV) Sensors
1. The Ultraviolet (UV) Sensor Market
Ultraviolet (UV) sensors and other environmental sensors are attracting increasing attention, and the global market is expected to exceed 1.1 trillion yen. In the global market size surveyed for six types of industrial sensors, gas sensors account for the largest share, followed by magnetic sensors and ultraviolet (UV) sensors in third place.
The market for ultraviolet (UV) sensors is expected to grow to 1.4 trillion yen in 2024, and the overall demand for ultraviolet (UV) sensors is expected to grow as well.
2. Ultraviolet (UV) Sensors Used in Sterilization Applications
Taking advantage of the sterilizing effects of ultraviolet rays, UV sensors have recently been widely used in public facilities such as airports and commercial facilities such as restaurants. As a result, there are more opportunities for general consumers to come into contact with ultraviolet light generating devices than ever before.
As the demand for sterilization increases in places used by the public, it is necessary to measure whether the UV light is strong enough for sterilization, while at the same time making sure that no harmful wavelengths of UV light are leaking out. Ultraviolet (UV) Sensors will be important for this purpose.
3. Flame Detection Using Ultraviolet (UV) Sensors
One product that utilizes ultraviolet (UV) sensors is a flame sensor that detects faint ultraviolet rays in flames. Applications include places where instantaneous fire detection is desired, such as clothing and bedding stores and smoking areas, where there is a risk of flames spreading. They are also used for flame detection in boiler burners.
Flame sensors are available in a variety of sensing methods, such as heat and infrared, but they present challenges, such as fire progression by the time they detect it. Ultraviolet (UV) flame sensors also have the challenge of potentially issuing false alarms depending on the machine generating the ultraviolet light. High-precision sensors are needed to detect fires quickly.