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NIST Traceable |
Each of our calibrated lamps is thoroughly tested to specification. Lamps are preconditioned and selected as necessary. The irradiance measurements are taken in our specially outfitted calibration laboratory. In the U.S., the National Institute of Standards and Technology (NIST) provides original uncertainties for their standard lamps. This range varies according to wavelength and lamp structure. There is an additional, small, uncertainty introduced during our procedure. Tables 1 and 2 show both (NIST and Newport’s) uncertainty values for the 1000 W QTH and 30 W deuterium lamps. |
Table 1 k = 2 Uncertainty Values for 63978 1000 W QTH Source |
| Wavelength (nm) |
Approximate NIST Uncertainty (%) |
Approximate Newport's Uncertainty* (%) |
| 250 |
2.23 |
2.8 |
| 350 |
1.35 |
2.5 |
| 654.6 |
1.01 |
2.5 |
| 900 |
1.34 |
2.5 |
| 1300 |
1.42 |
2.5 |
| 1600 |
1.89 |
2.8 |
| 2000 |
3.29 |
2.8 |
| 2400 |
6.50 |
2.8 |
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*Additional uncertainty due to calibration transfer.
Note: the uncertainty values can vary from time to time. |
Table 2 k = 2 Uncertainty Values for 63979 30 W Deuterium Source |
| Wavelength Range (nm) |
Approximate NIST Uncertainty (%) |
Approximate Newport's Uncertainty* (%) |
| 200 |
1.1 |
3.0 |
| 210 |
1.0 |
3.0 |
| 250 |
1.0 |
3.0 |
| 350 |
1.0 |
3.0 |
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*Additional uncertainty due to calibration transfer.
Note: the uncertainty values can vary from time to time. |
Produce Your Own Standard |
Lamps have a limited life. If you use the lamp frequently, we recommend that you purchase one or more non-calibrated lamps to produce your own working standard(s). |
Which Source Do I Choose? |
We offer three types of calibrated irradiance sources: |
Calibrated QTH Sources |
250 - 2400 nm or 300 - 2400 nm (lamp dependent) calibration range- Offered in 45 W, 200 W and 1000 W powers
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Calibrated Deuterium Sources |
250 - 400 nm calibration range- 30 W model, only
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Custom Sources/Calibrations |
Calibrations of your lamp- Custom standards
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Choose a lamp that provides irradiance levels close to what you would like to measure in your wavelength range of interest. Using a lamp that produces too much or too little irradiance puts higher demands on the linearity of your detection system. If you need an irradiance standard below ~330 nm, choose the deuterium lamp. This lamp provides more UV radiation than the QTH lamps (see Fig. 1), is calibrated down to 200 nm, and has the additional advantage of producing very little visible light. The low level of visible and near IR radiation reduces the out of band problems that plague UV calibration of instruments based on silicon photodiodes and other broadband detectors. |
Fig. 1 Spectral irradiance of calibrated lamps
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Calibrated QTH Sources |
Lamp Characteristics |
These coiled filament lamps are chosen for consistent irradiance over a long period and for low directionality in output. The polarization of the output is no more than 3%. The 200 and 1000 W lamps produce calibrated output from 250 to 2400 nm; the 45 W model produces calibrated output from 300 to 2400 nm. After a burn-in period, we measure the irradiance in open air using working standards derived from a set of NIST calibrated lamps. |
Data Supplied |
Spectral irradiance data in mW m-2 nm-1 units is provided at 2 nm intervals from 250 to 2400 nm spectral range for the 200 and 1000 W models, and 300 to 2400 nm for the 45 W model (in electronic form). NIST spectral irradiance standards are certified at fewer points than Newport’s Oriel Calibrated Lamps. The additional points we provide are based upon interpolation of the NIST data following a procedure published by NIST. Calibration data is supplied on disk and hard copy.
Each lamp also comes with a Report of Calibration. In addition to a listing of irradiance values, this report includes the lamp distance, lamp orientation, and laboratory temperature, as well as prescribed safety measures and directions for proper use. |
Power Supplies |
The irradiance information provided with calibrated QTH lamps is measured at a particular lamp current. It is very important, in order to maintain calibration, that these lamps be run by a highly regulated, constant current power supply. Our Radiometric Power Supplies, the 69900 Series, meet exceedingly demanding specifications. In addition to the superior performance, the 69900 Series Supplies have an RS 232 PC interface (IEE 488 interface is optional) so you have full access to all the control and monitoring features of the supply from your PC. |
Deuterium Lamps |
Lamp Characteristics |
These lamps emit calibrated radiation from 200 to 400 nm, but are particularly valued for their high output between 200 and 300 nm. If your measurement system reaches into the visible, you may use the 656.1 nm spectral peak as a wavelength calibration point. The peak irradiance is approximately the same as the deuterium irradiance level at 250 nm. This peak is commonly used to calibrate closed system spectrophotometers.
The radiation of deuterium lamps is a result of an electric arc discharge inside the deuterium gas. Newport’s Oriel Lamps are especially chosen for their long-term stability and the directional uniformity of their output. |
Data Supplied |
Each calibrated deuterium lamp comes complete with a calibration report. This report includes spectral irradiance values covering the range from 200 to 400 nm in 10 nm steps, a full list of test conditions to aid in calibration transfer, and directions for proper use. The data is supplied on disk and hard copy. |
Power Supply |
The 68942 Deuterium Power Supply is a highly regulated, constant current source, which provides the high voltage necessary for starting the lamp; it then settles rapidly to the 300 mA preset current. The prescribed constant current is crucial for maintaining the accuracy of the deuterium lamp's calibration. |
Open Air Lamp Mounts |
Our Calibrated Lamps are run in open-air. The mounts holding the lamps are simple, rod-mounted holders. They have a 1/4-20 tapped hole in the base for an optical rod. The appropriate lamp mount for your lamp is included with each source - or you can purchase individually. |
Calibration Services |
Please contact a Newport Sales Engineer for a quote on your custom calibration requirement. Typically, an annual calibration is recommended for calibrated lamps - although calibration dramatically varies with lamp usage. |
Safety Considerations |
When there is no clear selection of lamp, based upon irradiance level, the working environment may make the determination. The proper way to operate these lamps for calibration is in our open-air mounts. Therefore, the lower power calibrated QTH lamps are significantly easier to work with. These lamps are as safe as any bright domestic bulb except for the emission of ultraviolet. The 1 kW lamp is uncomfortably bright and heats any absorbing surface close to it; no flammable material should be placed near the lamp. Conversely, the deuterium lamp produces little visible light but very intense UV radiation. In all cases, UV goggles should be worn and exposure to the skin should be minimized. Always post appropriate safety signs. |
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All sources include lamp mount, power supply, your choice of calibrated lamp and all necessary cables. |
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