UVP J-225 BLAK-RAY - Manual

Blak-Ray® is a Registered Trademark of UVP, LLC
The significance of meter readings depends on several considerations:
1. The absolute spectral response of the meter; that is, how the meter "weighs" the
different wavelengths of radiation with respect to perfect response and to one
another;
2. The spectral output of the emitter; that is, the range of different wavelengths of
radiation produced by the emitter and their relative proportions; and
3. The spatial response of the meter; that is, how the meter responds to radiation
arriving at the sensor surface at angles other than the perpendicular.
Absolute measurements can only be obtained by using a properly calibrated meter. UV
meters can be calibrated against a line source such as a 365nm line source so that it
provides a direct reading of irradiance from this type of source. Other sources can be
measured, but the meter reading will have to be adjusted as the indication of the meter
depends not only on the irradiance at the sensor from the source but also on the
interaction of the wavelength distribution of the light source and the meter spectral
response. If a meter is calibrated to provide correct readings with a particular lamp, it will
not provide correct values for lamps with different spectral distributions. However,
relative comparisons of lamps with identical spectral distributions of UV light can be
made with any stable meter, regardless of the calibration method used, as long as the
meter has sensitivity in the desired wavelength region.
The J-221 is calibrated to accurately read the irradiance from longwave phosphor coated
lamps. If used to measure irradiance from a 365nm line source (B-100 type lamp), it will
read approximately 35% higher than the actual irradiance. To obtain the true value, the
reading should be multiplied by 1/1.35 = .74.
CALIBRATION
For best accuracy, ultraviolet meters should be re-certified every six months. Call UVP's
Calibration Department at 800-452-6788 for recertification. For recalibration or repairs
due to dropping or exposure to moisture (keeps cells dry), return the complete meter to
the factory prepaid. A Returned Goods Authorization (RGA) number must be obtained
from UVP’s Customer Service prior to returning any product. The unit will be calibrated
by a standard traceable to the NIST. Calibration charge is nominal. The average
turnaround time is ten days. NOTE: In order to maintain traceability to NIST
standards, meters must be returned to UVP for calibration. UVP does not stand
behind unauthorized calibrations.
PART NUMBERS
J-221, P/N 97-0003-01, Longwave Meter J-225, P/N 97-0004-01, Shortwave Meter
UVP, LLC 2066 W. 11 th St. Ultra-Violet Products Ltd., Unit 1
Upland, CA Trinity Hall Farm Est., Nuffield Rd
USA Cambridge CB4 1TG UK
Tel: (800) 452-6788; (909) 946-3197 Tel: 44(0)1223-420022
Fax: (909) 946-3597 Fax: 44(0)1223-420561
Web Site: www.uvp.com
81-0032-01 Rev G
J-221 AND J-225 BLAK-RAY®
ULTRAVIOLET INTENSITY METERS
USER INSTRUCTIONS
BLAK-RAY® ULTRAVIOLET METERS are hand held photovoltaic devices used
for measuring the intensity of ultraviolet energy emitted from ultraviolet lamps.
Only ultraviolet plus some infrared registers on the meters; visible light of less
than 40 foot candles does not. When infrared or intense visible light is present, it
can be eliminated from the readings as detailed under "Infrared Interference". A
certification statement of calibration using a standard traceable to the National
Institute of Standards and Technology (NIST) is provided with each meter.
IMPORTANT: Recalibration is recommended at least every six months.
TOLERANCES
Meter readout is in radiometric units, i.e., microwatts per square centimeter
(µW/cm²). This new silicon detector has an improved linearity tolerance of ±10%.
The short-term repeatability is better than ±1% under isothermal conditions. The
measurement accuracy is additionally limited by the ±2.6% tolerance of the NIST
standard source. The secondary standards used for calibration are traceable to
NIST. The minimum detector limit is 20 µW/cm².
ASSEMBLY INSTRUCTIONS
The sensor cell plugs directly into the receptacle on the top of the meter housing.
To make readings remote from the metering unit, the extension cord should be
plugged into the receptacle with the red and black plugs aligned with their
corresponding holes for proper polarity. The sensor cell plugs into the other end
of the extension cord in the same manner.
TO READ THE SCALE
The meter should always be used with the scale facing vertically. Before taking
readings, the meter zero should be checked with the sensor cell unplugged and
the scale vertical. Adjust to zero whenever necessary by means of the screw
located directly beneath the scale. Meters have two scales; use the switch to
select the A or B scale. Ranges on the longwave meter (J-221) are 0 - 12 and 10
- 60 (B scale). Ranges on the shortwave meter (J-225) are 0 - 24 (A scale) and
20 - 120 (B scale). To obtain µW/cm², multiply reading by 100 (R X 100 =
µ W/cm² where R = meter reading).