What is Candela (cd)
Candela (symbol: cd) is a unit of measurement used in the lighting industry to quantify luminous intensity. It represents the amount of light emitted by a light source in a specific direction. The candela value is not affected by the distance from the light source but is influenced by the opening angle of the light beam.
Maybe You Are Interested In
- Ceiling-mounted RZ037 PIR occupancy sensor dimmer for 220V power
- 3A maximum working current with 660W rated load
- LUX button controls light-sensor ON/OFF and user-set dimming brightness
- Ceiling-mounted RZ037 PIR occupancy sensor dimmer for 110V power
- 3A maximum working current with 330W rated load
- LUX button controls light-sensor ON/OFF and user-set dimming brightness
- Ceiling-mounted PIR occupancy sensor with dry-contact relay output
- 12/24VDC or 12/24VAC low-voltage supply
- COM, NO, and NC isolated relay contacts for EMS, HVAC, and building control inputs
- Low-voltage DC recessed ceiling-mounted microwave motion sensor switch
- 12 VDC / 24 VDC input with 10-30 VDC range
- 10A max work current with adjustable time delay, Lux threshold, and sensitivity
- Higher-load recessed ceiling-mounted microwave motion sensor switch
- 100-265 VAC line-voltage input, 10A model
- 5.8 GHz microwave sensing with adjustable time delay, Lux threshold, and sensitivity
- Recessed ceiling-mounted microwave motion sensor switch
- 100-265 VAC line-voltage input, 5A model
- 5.8 GHz microwave sensing with adjustable time delay, Lux threshold, and sensitivity
- Low-voltage DC ceiling-mounted microwave motion sensor switch
- 12 VDC / 24 VDC input with 10-30 VDC range
- 10A max work current with adjustable time delay, Lux threshold, and sensitivity
- Higher-load ceiling-mounted microwave motion sensor switch
- 100-265 VAC line-voltage input, 10A model
- 5.8 GHz microwave sensing with adjustable time delay, Lux threshold, and sensitivity
- Ceiling-mounted microwave motion sensor switch
- 100-265 VAC line-voltage input, 5A model
- 5.8 GHz microwave sensing with adjustable time delay, Lux threshold, and sensitivity
- Wireless switch and receiver kit for indoor ON/OFF lighting control
- 100-230VAC, 50/60Hz receiver with 5A rated current
- CR2032-powered wireless switch with 2.4GHz communication
- Occupancy (Auto-ON/Auto-OFF)
- 12–24V DC (10–30VDC), up to 10A
- 360° coverage, 8–12 m diameter
- Time delay 15 s–30 min
- Light sensor Off/15/25/35 Lux
- High/Low sensitivity
- Auto-ON/Auto-OFF occupancy mode
- 100–265V AC, 10A (neutral required)
- 360° coverage; 8–12 m detection diameter
- Time delay 15 s–30 min; Lux OFF/15/25/35; Sensitivity High/Low
- Auto-ON/Auto-OFF occupancy mode
- 100–265V AC, 5A (neutral required)
- 360° coverage; 8–12 m detection diameter
- Time delay 15 s–30 min; Lux OFF/15/25/35; Sensitivity High/Low
- 100V-230VAC
- Transmission Distance: up to 20m
- Wireless motion sensor
- Hardwired control
- Voltage: 2x AAA Batteries / 5V DC (Micro USB)
- Day/Night Mode
- Time delay: 15min, 30min, 1h(default), 2h
- EU plug power adapter
- UK plug power adapter
- US plug power adapter
- 5V DC
- Transmission Distance: up to 30m
- Day/Night mode
- 5V DC
- Transmission Distance: up to 30m
- Day/Night mode
The opening angle refers to the width or narrowness of the light beam emitted by the source. A smaller opening angle, such as 10°, concentrates the light, resulting in a higher candela value. Conversely, a larger opening angle, like 50°, spreads the light over a wider area, leading to a lower candela value.
Note that Candela is a measure of luminous intensity, which is distinct from luminous flux. Luminous flux is measured in lumens (lm) and represents the total amount of visible light emitted by a source in all directions. In contrast, candela focuses on the intensity of light emitted in a specific direction.
Looking For Motion-Activated Energy-Saving Solutions?
Contact us for complete PIR motion sensors, motion-activated energy-saving products, motion sensor switches, and Occupancy/Vacancy commercial solutions.
Frequently Asked Questions
What Is the Cd in Light Intensity
The candela (symbol: cd) is the SI base unit of luminous intensity. It represents the power emitted by a light source in a specific direction, taking into account the luminosity function. For example, a typical candle emits light with a luminous intensity of approximately 1 cd.
What Is the Difference Between Cd and Lux
Candela refers to the amount of light emitted by a fixture in a specific direction, while lux measures the level of light that illuminates a surface.
Is CD the Same as Lumen
1 candela is equivalent to 12.57 lumens. However, it is not advisable to directly compare the values of lumens and candela when it comes to lighting devices.
How Do You Calculate Candela CD
The calculation can be done using the formula 1lm = 1cd * 1. This means that 1 lumen is equal to 1 candela. In other words, a light source with an intensity of 1 candela will produce 1 lumen of luminous flux in a sphere with a surface area of 1 square meter.
How Many Candela Is a 100 Watt Bulb
The luminous intensity of a 100 watt unidirectional bulb is equivalent to 100 candela.
How Many Watts Is 1 Candela
In 1979, the General Conference on Weights and Measures (CGPM) established a new definition for the candela (cd). It is now defined as the luminous intensity, in a specific direction, of a source that emits monochromatic radiation with a frequency of 540 × 10^12 hertz. Additionally, the radiant intensity of this source in that direction is equivalent to 1/683 watt per steradian.
How Many Candelas Is a Lightbulb
For a more up-to-date comparison, a standard incandescent lightbulb typically produces around one candela per watt.
Is Higher or Lower Candela Better
A higher candela rating indicates that the light emitted is more intense, allowing it to travel a longer distance. Torches with high candela ratings are ideal for situations where visibility is reduced, such as in smoke or fog, and when a concentrated beam is desired.
