Buying a UV Light Meter – Caveat Emptor – Buyer Beware
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One major usage of UV light began in the Semiconductor Industry, in 1975. Only two companies manufactured instruments to measure the UV light specifically necessary for that process. Optical Associates (OAI) founded by Jerry Bachur and George Richardson, located in Santa Clara, CA, on the West Coast and International Light, located on the East Coast. OAI, at that time, dominating the majority portion of this business. UV light was a critical step in making integrated micro-devices better known today as “micro-chips or microprocessors.” Without these UV measurement instruments, arguably, we would not have the far reaching electronics uses we have today.
Absolute accuracy and repeatable UV measurements were and still play a critical role in “micro-chip” manufacturing. Critical elements of UV light consisting of wavelength, intensity, and energy had to be precisely measured and monitored otherwise hundreds of dollars were lost and time wasted. George Richardson, as mentioned above, is an engineer with an extensive background in UV light designed OAI’s UV light meter and established the standards used by the calibration lab that was essential which semiconductor manufacturers, demanded, in order for them to be successful. Currently, Mr. Richardson is the owner of G&R Labs, founded in 1994, in Santa Clara, CA whose only business is manufacturing UV light meters and calibrating meters to a recognize and accepted NIST standard.
Since 1975, the uses for UV light applications has dramatically increased ranging from micro-chips manufacturing to UV disinfection. Along with this expansion, are the number of UV light meter manufacturers. This is where “Caveat Emptor” comes in. Many of these UV meters, primary from the Far East and some from Europe, have poorly designed electronics, sensor packages and provide a measurement number based upon “who knows what.” These meters are priced lower but without offering users accurate and repeatable UV measurements. As an example, just look on Ebay. Because of this rapid expansion many of the users for these applications have limited knowledge of UV light and are unaware of what goes into making a UV light meters. As a result, price becomes the driving point until problems arise. Viola, the reason for this article.
One key when purchasing a UV light meter is in the design. Calibration, calibration and calibration is everything. Two essential components are absolutely necessary to provide the user with an accurate, repeatable, and reliable UV light meter. First, one needs to calibrate the meter to a known and accepted worldwide standard. However, in order to achieve this kind of calibration, one must have the calibration lab resources to achieve the accuracy required, <0.5% to the NIST standard. Secondly, the design of the electronics must be free from electronic interference, in order for the UV meter to be calibrated and re-calibrated over time. Finally, the sensor package must be design using components that work together to insure the wavelength accurately measures the light source being used and then not degrading overtime with usage.
Another key consideration when purchasing a UV light meter deals with post purchase. There are also two essential considerations to be addressed. First, if you have processing problems, the light source comes into question and is there someone I can speak with that understands UV light and my UV light meter? Mr. Richardson receives phone calls on a daily basis from users incurring problems across a wide variety of applications using UV light. Having an accessible contact is definitely a plus. The second post purchase consideration is calibration and repair. Sensor packages (probes and wires) are attached to the electronics. People have a tendency to swing the probe as a lasso not realizing that tiny wirers are used in the probe cabling. These wirers can break if not handled correctly. If they should break, where do you send the meter to be fixed? Which leads into the next consideration, calibration. If a wire should break, the meter must be re-calibrated. If the UV meter is a low end meter is the business local or off shore that will repair it, if it can be repaired? Will the meter provide you with the same readout that you had prior to the repair? Whether the meter is sent in for repair or is needed to be periodically re-calibrate, as suggested, the question of calibration standard is critical. The only worldwide accepted standard for measuring UV light is the National Bureau Institute of Technology (NIST). That is the gold standard. Any other standard, if used, will provide a relative measurement and probably unique to the manufacturer.
Finally, another important consideration is the quality and quality control that goes into manufacturing a UV light meter. In the design, extreme care must be given in selecting all components whether they are in the electronics or in the sensor. Only through diligent quality control will these meters meet design specifications to insure an accurate, repeatable and reliable UV meter that can be calibrate to NIST standards. This is especially true with sensor packages components.
Key questions when considering purchasing a UV Light Meter:
• Is the meter initially calibrated to the NIST standard or an unknown number
• Where do I send the meter to be re-calibrated
• When re-calibrated is the same NIST standard used
• What is the turnaround time for calibration
• Is the meter’s electronics designed for re-calibration over the long term
• Will the sensors degrade over time leading to erroneous measurement errors
• Are different wavelength probes interchangeable with the electronic or do I have to purchase a another meter and probe
A word of caution. It is G&R Labs firm belief that all UV light meters should automatically include a NIST Calibration Certificate at no additional cost. Some UV meter manufacturers do not include this certificate and cannot provide one. Other manufacturers only include a certificate if purchase separately. Also, on the surface, it may appear a lower price meter providing a relative number is the way to go but only the long term will determine the cost.
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G&R Labs, 2395 De La Cruz Ave., Santa Clara, CA 95050 Tel: (408) 986-0377 website: grlabs.com