Overview
Photometry is a branch of optical measurement that focuses specifically on light as perceived by the human visual system. Unlike radiometry which measures all electromagnetic radiation, photometry weights measurements according to the spectral sensitivity of the human eye (defined by the CIE photopic and scotopic luminosity functions). This specialized measurement approach is essential because human vision doesn't respond equally to all wavelengths of light. Modern photometry traces its origins to the early 20th century with the development of standardized observer functions by the International Commission on Illumination (CIE).
Key Features
Photometric measurements focus on four primary quantities: luminous intensity (measured in candela), luminous flux (lumens), illuminance (lux), and luminance (candela per square meter). These measurements differ from radiometric equivalents by incorporating the human eye's spectral sensitivity curve. Specialized instruments called photometers are used for these measurements, ranging from simple handheld devices to complex laboratory equipment. The accuracy of photometric measurements depends on proper calibration against standard light sources and consideration of measurement geometry. Many industries rely on standardized measurement conditions defined by organizations like CIE, ISO, and ANSI.
Application Areas
In lighting design and manufacturing, photometry is crucial for specifying and testing luminaires. Automotive industries use photometric testing for headlight and signal light compliance. Display manufacturers rely on photometry to quantify screen brightness and contrast ratios. The architectural lighting sector uses photometric data for space illumination planning. In astronomy, photometry helps measure stellar magnitudes. Industrial applications include quality control for light sources and reflective surfaces. Regulatory bodies often require photometric testing for product certification and safety compliance.
Precautions
Accurate photometric measurement requires attention to several technical factors. Instruments must be properly calibrated against traceable standards. The spectral power distribution of the light source affects measurements, especially when testing LEDs or other non-continuous spectrum sources. Measurement geometry is critical - factors like distance, angle, and field of view must be controlled. Ambient light conditions can affect measurements, requiring darkroom conditions for some tests. Users should be aware that different standards may apply to different applications (e.g., automotive lighting vs. general illumination).
B2B Procurement Guide
When sourcing photometric equipment or services, consider the specific measurement needs of your application. Basic quality control may only require simple photometers, while R&D applications might need spectroradiometers with photopic correction. Verify that equipment meets relevant industry standards (CIE, ISO, IES, etc.). For measurement services, look for accredited laboratories with proper calibration certifications. Pricing varies significantly based on accuracy, features, and brand reputation. Consider total cost of ownership including calibration services and software updates.
Related Manufacturers
- 主营：[]
- 主营：单人防护装备包、个人防护包、移动执法装备、光照强度测量、移动执法包、水污染监测设备、红外夜视仪、热成像仪、便携式超声波明渠流量、油烟检测仪、VOC检测仪、qdf-6风速仪、恒流大气采样器、移动源执法设备、在用车尾气分析仪、不透光烟度计、车用氮氧化物分析仪、OBD检测仪、FID检测仪、便携式水质自动采样器、水质快检试剂包、多普勒流量计、转子流速仪、红外气体泄漏检测仪、紫外线强度仪
- 主营：超声波流量计、水质检测仪器、在线COD氨氮总磷总氮测试仪、水质分析仪、水质采样器、多普勒流量计、多参数水质检测仪、水深探测仪、水质流速仪、手持式电波流速仪
- 主营：测试仪、测定仪、触摸屏、光度仪、光度计、外分光光度、光谱仪、分析仪器、光谱辐射计、分析检测仪、水质检测仪、水质分析仪、分光检测仪、检测分析仪、光谱分析仪、紫外辐射照度计、双光束光学系统、数显双光束仪器
- 主营：紫外可见分光光度计、原子吸收分光光度计、原子荧光光度计、超微量分光光度计、原子荧光光谱仪
- 主营：检测仪、voc测试仪、油烟测试仪、自动监测仪、油烟分析仪、油烟监测仪、大气采样器、气体检测仪、水质分析仪、烟气分析仪、明渠流量计、水质采样器、环境检测仪
- 主营：培养箱、分析仪、检测仪、测量仪、报警仪、酸度计、风速仪、蓝牙、称重系统、室内检测仪器、甲醛检测、测定仪、声校准器、酸碱浓度计、流量计、采样器、消解器、机器人、振动检测分析仪、测试仪、环保第三方检测、环境检测、综合采样器、生物安全柜、浊度仪
- 主营：食品安全检测仪、ATP荧光检测仪、农药残留检测仪、兽药检测仪、蜂蜜检测仪、粮食安全检测仪、食品检测仪、检测仪器
- 主营：油气回收检测仪、便携式活性炭碘值检测、烟花爆竹探测器、便携式明渠流量计、单人防护装备、个人剂量报警仪、氢火焰离子化检器、水质快检试剂包、手持热电风速仪、水样采样设备、便携式噪声检测仪、多参数气体检测仪、热成像泄漏检测仪、土壤重金属检测仪、移动源执法监测设备、水质指纹预警溯源仪、便携式烟气分析仪、便携式恶臭检测仪、便携式油烟检测仪、林格曼黑度检测仪、消耗臭氧层物质检测仪、应急防护包、辐射防护包、个人防护包、油气回收多参数检测仪
- 主营：便携式五参数水质检测、个人防护包、便携式水质采样器、快检试剂、便携式多参数水质检测、便携式明渠流量计、激光测距仪、恒温恒湿称重系统、氨氮六价铬水质检测仪、油烟检测仪、烟尘烟气检测仪、便携式多气体检测仪、紫外辐射照度计、激光粉尘检测仪、风速仪
- 主营：气体检测仪、水质采样器、水质分析仪、烟尘烟气测试仪、大气采样器、超声波明渠流量计、恒温恒湿称重系统、个人防护包、油气回收检测仪、离心机、蓝牙、光泽度仪、负氧离子检测、摇床、微生物快速检测、声校准器、声级计、分析仪、单人防护装备、移动执法包、采样设备、油烟检测、气体、水质、明渠流量计
- 主营：甲醛检测仪、防护箱、干燥箱、离心机、臭氧计、加热器、均浆机、黑度仪、多通道采样器、传感器、流量计、采样器、传声器、频率计、烟度计、机器人、控制器、测试仪、无人机、防护包、探测器、浊度仪、抽滤仪、检测仪
- 主营：测油仪、水质测定仪、BOD测定仪、可见分光光度计、COD消解器、氮吹仪、硫化物酸化吹气仪、索氏提取器、蒸馏仪、振荡器、恒温恒湿称重系统、明渠流量比对装置、土壤研磨机、土壤团聚体分析仪、烟尘烟气分析仪、大气采样器、林格曼黑度计、综合压力流量校准仪、北京踏实、洗瓶机、固相萃取仪
- 主营：水浴箱、分析仪、监测仪、报警仪、臭氧计、触摸屏、控制器、黑度仪、电子秤、测温仪、测定仪、传感器、物安全、计数器、流量计、采样器、消解器、照度仪、干燥筒、机器人、测试仪、离心机、光离子、防护包、浊度仪
- 主营：分析仪、采样器、监测仪、测量仪、光电光度、消解器、粉尘仪、回流管、防护箱、检测仪、培养箱、风速仪、黑度仪、微波炉、测定仪、遥测仪、萃取仪、指数仪、流量计、防护包、测油仪、真空泵、无氧培养、加热装置、水质监测
- 主营：检测仪、声级计、智能红外、静电能谱、职业卫生、水质自动、生物安全柜、电子流量计、水质采样器、红外测温仪、烟气测试仪、气体分析仪、烟尘采样器、明渠流量计、微生物采样器、气溶胶采样器、厨房油烟检测