501A-UV Biometer

MODEL 501A- UV Biometer is the continuation of the line of Robertson-Berger Weatherproof meters, that have been employed in the worldwide network for UV-B monitoring. The UV-Biometer has been designed by D.Berger and M.Morys, based on the experience gained during the Robertson-Berger meter design (Berger 1976) and of research focused on the temperature dependency and stabilization of the Robertson-Berger UV-B sensor (Blumthaler, Ambach, Morys, Slomka 1989).

Find out how to submit your ultraviolet data to the World Ozone and Ultraviolet Radiation Data Centre

Model 501-UV Detector- technical specifications

Spectral response	Figure 1
Measurement range	0...9.99 MED/HR
Resolution	better than 0.01 MED/HR
Accuracy	within +/- 5% for daily total
UV signal output	compatible with Model 501 Recorder w/software V1.4A
Sensor temperature output	as above
Operating environment	outdoors
Operating ambient temperature	-20...50°C
Storage temperature	-40...70°C
Temperature sensor measurement range	-50...100°C
Temperature stabilization of the filter max. temperature differential:	60°C heating above ambient 25°C cooling below ambient
nominal sensor temperature	25°C
stabilization accuracy	±1°C, ±0.2°C stability
temperature settling time	<5 minutes for 20°C change
Cable length	50 ft. (15m) standard, 200ft max
Diameter of the detector	6" (15 cm)
Height of the detector	5" (13 cm)
Weight	2 lb. ( 0.9kg)

MODEL 501A-UV detector has an analog output allowing connection to a data logger. (The 501-UV detector has a digital output)

All the specifications for the 501-UV apply to the 501A-UV with the following additions:

UV signal output	0...+2.5V, 0.250 V/(MED/HR), 0.5mA max
Sensor temperature output	-2.5...+2.5V, 1V=25°C, 20mV/°C sensitivity,0.5 mA max
Power requirements	5.5...25V/5mA max for signal circuitry 11...15V/1A max for temperature stabilization
Temperature settling time	<10 minutes for 20°C change

Fig.1 UV-Biometer Detector Models 501 UV and 501A-UV

MODEL 501- UVA measures long wavelength UV (320 to 400 nanometers).This band accounts for 90% or more of the total irradiance shorter than the visible reaching Earth. The remainder of the UV irradiance is in the UVB, which is shorter than 320 nm.

A high proportion of UVA radiation (UVAR) emanates from the sky, so that the good cosine response of the meter is important.

UVAR is unaffected by ozone, therefore, the rapid changes in UVBR which occur as the ozone effective thickness changes with sun angle do not occur with UVAR. This difference in the time course of these two UVR regions is distinctive and important.

The meter output gives irradiance in terms of milliwatts per cm². Integrating the irradiance over a period of time gives the dose in terms of joules per cm². The meter can integrate in time periods between 1 minute and 1 hour.

UVA radiation fades dyes and paints, degrades plastics, and produces various biological effects.

Model 501-UVA Detector- technical specifications

Spectral response	Figure 1
Measurement range	0-10mW/cm2
Resolution	better than 0.01mW/cm2
Accuracy	within +/- 5% for daily total
UVA signal output	compatible with Model 501 Recorder w/software V1.4A
Sensor temperature output	as above
Operating environment	outdoors
Operating ambient temperature	-20...50°C
Storage temperature	-40...70°C
Temperature sensor measurement range	-50...100°C
Temperature stabilization of the filter max. temperature differential:
heating above ambient	60°C
cooling below ambient	25°C
nominal sensor temperature	25°C
stabilization accuracy	±1°C, ±0.2°C stability
temperature settling time	<5 minutes for 20°C change
Cable length	50 ft. (15m) standard, 200ft max
Diameter of the detector	6" (15 cm)
Height of the detector	5" (13 cm)
Weight	2 lb. ( 0.9kg)

MODEL 501A-UVA detector has an analog output allowing connection to a data logger. (The 501-UVA detector has a digital output)

All the specifications for the 501-UVA apply to the 501A-UVA with the following additions:

UV-A signal output	0...+2.5V, 0.250 V/(mW/cm²), 0.5mA max
Sensor temperature output	-2.5...+2.5V, 1V=25°C, 20mV/°C sensitivity,0.5 mA max
Power requirements	5.5...25V/5mA max for signal circuitry 11...15V/1A max for temperature stabilization
Temperature settling time	<10 minutes for 20°C change

Fig.1 UV-Biometer Detector Models 501 UVA and 501A-UVA