USPRO Lamp settings.

How to interpret USPro Lamp settings;

LAV/MAV/SAV

Flashes 4 / 5 / 8

Frequency (Hz) 5/ 5 / 5

Bursts/Flash 1/ 1 / 2

A Burst is the process that ignites the Xenon gas in the lamp. A Flash is a pulse of already ignited gas. For the USPro for LAV there is one Burst which consists of 4 Flashes. It is difficult for the human eye to visually see the individual flashes, but one can audibly hear a "click" for each flash. In the setting above for LAV the lamp would come on, you would hear 4 clicks and the lamp would go off. In the setting above for SAV the lamp would come on, you would hear 8 clicks and the lamp would go off then the lamp would come on again you would hear 8 clicks and the lamp would go off .

The Frequency is the rate at which the lamp capacitor charges. This setting is always 5 for each Area View for each sensor.

Ho to interpret USPro Lamp settings

LAV/MAV/SAV

# Flashes 4 / 5 / 8

Frequency (Hz) 5/ 5 / 5

Bursts/Flash 1/ 1 / 2

A Burst is the process that ignites the Xenon gas in the lamp. A Flash is a pulse of already ignited gas. For the USPro for LAV there is one Burst which consists of 4 Flashes. It is difficult for the human eye to visually see the individual flashes, but one can audibly hear a "click" for each flash. In the setting above for LAV the lamp would come on, you would hear 4 clicks and the lamp would go off. In the setting above for SAV the lamp would come on, you would hear 8 clicks and the lamp would go off then the lamp would come on again you would hear 8 clicks and the lamp would go off .

The frequency determines the rate at which the lamp capacitor recharges.

Data reliability between 850-1050nm for the USPRO instrument

Question: What is the reliability of the data shown above 850nm for a USPRO.

Answer:

The USPRO uses a lamp module that contains three Xenon lamps. These are individually filtered such that energy from 350nm to 1050 is emitted during the flash burst and all wavelengths are then detected simultaneously. The actual spectral repeatability, stated in terms of maximum Peak to Peak span varies by wavelength. The brochure states a Maximum P-P of 0.2 between the interval of 435nm and 695nm, which is where the majority of the Tristimulus Weighting occurs.

For the wavelength range 700nm to 895nm typical Maximum P-P would be 0.4

For the wavelength range 900nm to 1020nm the typical Maximum P-P would be 2.0

For the wavelength range 1025 to 1050 the typical Maximum P-P would be 10.0

Note that the maximum difference usually occurs near the end of the stated wavelength above. For example a plot of the repeatability shows a fairly continuous smooth rise from 700nm through 1020nm. Above 1020 the repeatability becomes random throughout the wavelength range at the Maximum P-P level. The gating factor at the upper wavelengths is not the Xenon source as much the sensitivity of the silicon detectors.

Can NML White Standard be used with USPro

Quesiton: Can I send my USPro White tile to my National Meteorology Laboratory and have it calibrated, then enter the calibrated values into the firmware for the instrument to use?

Answer:

The everwhite tile that is supplied with the USPro is calibrated relative to PTFE that was measured on a USPro. This is how ASTM specifies that the Top of Scale be assigned. As a proficiency check we measure a white tile and compare the reading to how NIST read that tile. If there is no difference within the uncertainties of both measurements then there is no difference between the assignments.

I would suggest that your customer do the same. They can either send their tile, or purchase a new tile and send it to NIST/NPL. then when the tile is returned they can standarize the sensor with our tile then read the NIST/NPL assigned tile and compare results. They can do with for both RSIN and RSEX.

Measuring the emission of LED's using an UltraScan PRO

Question: How can I measure the emission of an LED using my USPRO? I talked with your Technical Support team and they said it could not be done.

 

 

 

Answer:

 

 

 

Our technical support team is not equipped to handle questions about non-standardl uses of HunterLab instruments. The UltraScan PRO is designed to measure Transmitted or Reflected light from a specimen using methods described by the CIE and ASTM. Measuring emitted light is not a recommended use of the UltraScanPro and we do not offer any software products that would allow you to easily measure emitted light per CIE or ASTM methods to directly calculate Tristimulus or CIELUV coordinates.

 

 

 

We do have the ability to scan the array to record the response from emission sources such as your LED's but this moves from the realm of typical support over to what we term PAR (Paid Application Research). In simple terms, you would have to pay a HunterLab technician to train you in how to configure the instrument to collect this data so that it provides meaningful results.

 

 

 

The USPRO Diagnostics software that was supplied with the instrument would allow to scan the array without flashing the lamp and then you could paste the results into a spreadsheet or notepad. This is done by establishing a connection between the instrument and the diagnostics program, then clicking on the Raw Data Tab, checking the box labeled Dark Noise, then clicking on the Flash icon.. Results are automatically copied to the clipboard. Use the Edit | Paste command to copy the data to a new location.This would be raw pixel data not corrected for bandpass or wavelength postion. I'm not sure how useful this data would be to you.

 

 

 

HunterLab does offer CMR -2900 an option that consists of ActiveX/OCX Control program for $296

 

Used on: USPRO Provides an ActiveX/OCX control for interfacing to a HunterLab UltraScan PRO sensor. A separate HTML-based help file that describes the control interface is also provided, along with code samples for Visual Basic and Excel that illustrate how to communicate with the instrument. This program provides the ability to standardize and read spectral data (only) for Standards and Samples. The User is responsible for any subsequent color calculations from the spectral data. This Active X/OCX interface allows the User to configure a unique data collection and reporting solution while using HunterLab's color measurement expertise and sensor. The ActiveX/OCX is designed for use with Windows XP, VISTA and WIN 7 32/64, WIN 8 operating systems. Delivery:2 weeks

 

 

 

You could purchase this CMR and write your own data collection program to measure the emission of your LED's

 

 

UltraScan PRO Brochures

UltraScan PRO Brochure

UltraScan PRO Brochure (Spanish)

UltraScan PRO Brochure (Portuguese)

USPro Spectral Repeatability

HunterLab uses the term "peak to peak" (P-P) to represent the maximum range for a consecutive group of 20 readings of the Instrument Standard White tile for a Reflectance Specular Included test or an empty transmission compartment for a Transmission test.  To simulate this testing Configure EasyMatchQC to take 20 timed readings at 10 second interval. When the readings are complete then for each wavelength between calculate the peak to peak by subtracting the minimum %R or %T reading from the group of 20 from the Maximum %R or %T reading from the group of twenty and report the difference.  The maximum allowable P-P for a given wavelength range is shown in the table below.

 

Maximum P-P per λ

385nm-405nm 0.5 %T
410nm-430nm 0.3 %T
435nm-695nm 0.2 %T
700nm-765nm 0.3 %T
770nm-815nm 0.4 %T
820nm-840nm 0.5 %T
845nm-955nm 1.0 %T
960nm-970nm 2.0 %T
975nm-995nm 3.0 %T

0 %R or %T at 350nm

A sensor reading 0 at 350nm can usually only be remedied by increasing signal levels or replacing the sphere, this is a different issue than reading 0 at any other wavelength. Technically 350nm and 355nm have no weighting in all the Observer tables so your Tristimulus and Scale and Index results are not affected by this issue.

If you notice an unexpected 0 %R or %T at any wavelength above 420nm then suspect a communication error between the LSUP and SPSP boards in the sensor.

If you notice a long string of 0's from 350nm to 400nm or up to 420nm then check the UV Filter position as it may be inserted into the light path.

USPro Flash settings

Question: In the past I have seen USPro with Flash settings 2/5/8 and now see settings Flashes 4 / 5 / 8, what do those settings mean and why are they different?

Answer:

As of April 2017 the typical settings are

# Flashes 4 / 5 / 8

Frequency (Hz) 5 / 5 / 5

Bursts/Flash 1 / 1 / 2

A Burst is the process that ignites the Xenon gas in the lamp. A Flash is a pulse of already ignited gas. For the USPro for LAV there is one Burst which consists of 4 Flashes. It is difficult for the human eye to visually see the individual flashes, but one can audibly hear a "click" for each flash. In the setting above for LAV the lamp would come on, you would hear 4 clicks and the lamp would go off. In the setting above for SAV the lamp would come on, you would hear 8 clicks and the lamp would go off then the lamp would come on again you would hear 8 clicks and the lamp would go off . Frequency is the rate at which the capacitor charges between the Bursts.

HunterLab believes that due to ROHs the glass composition of the xenon flash tubes has changed which has reduced the UV output of the lamp. To compensate for the reduced UV output and still be able to perform a Ganz Whiteness UV Calibration the number of flashes per burst has been increased for LAV.

If you install a new lamp (XPLM) into an older USPro you may need to increase the number of Flashes for LAV in order to UV calibrate.

Peak to Peak spectral repeatability

Question: What does it mean maximum peak to peak 0.20 between 435nm and 695nm on the USPro specifications?

Answer: HunterLab uses the term "peak to peak" to represent the maximum range for a consecutive group of 20 readings of the Instrument Standard White tile. Configure EasyMatchQC to take 20 timed readings at 10 second interval. When the readings are complete then for each wavelength between from 435nm to 695nm calculate the peak to peak by subtracting the minimum %R or %T reading from the group of 20 from the Maximum %R or %T reading from the group of twenty and report the difference, if the difference is above 0.20 then the instrument may need adjustment.

Didymium Tolerance EasyMatch report and Users Manual USPro

Question:

The users manual shows the didymium tolerance to one decimal point and the EasyMatch QC Diagnostics program shows to two decimal points. For example

@430nm the manual says by no more than 1.2 %T and the QC Diagnostics shows +/- 1.25 %T These values are not equivalent, which is correct.

Answer:

significant digits have significance. The USPro has a fixed reporting using double precision floating point. Meaning every measurement is calculated to 64 decimal points. EZMQC then rounds those readings to report from 0 to 4 decimals places based on user preference.

The manual states the acceptance tolerance with the words "by no more than" which is equivalent to saying "less than or equal to". Taking the 430nm tolerance as an example we specify 1.2 %T as the tolerance. Mathematically this means all of the following possibly results from EZMQC would produce a Pass +/- 1.2, +/- 1.24, +/- 1.249, +/- 1.2499

The author of the report form felt that aesthetically a tolerance of 1.24 was not as pleasing as 1.25, so approximately three thousands of a nanometer acceptance to the tolerance at each test point was added when the Didymium Filter report was modified. For an average filter curve, remember the tolerance width does vary slightly by the actual filter being used since there is a nominal thickness variation from filter to filter, a 1.249 %T shift equates to a 0.898 nm shift and a 1.254 %T shift equates to a 0.901 nm shift. I would humbly suggest that this difference is quite a bit less than the measurement to measurement variance, so this change isn't causing any significant change in determining the wavelength performance of the instrument.

My guess is that we may need at some point in the future to either make a change to EZMQC or to the Users Manual if the explanation above does not satisfy the customer.

Does changing the wavelength range or interval affect calculation of USPRO color values?

FAQ: "For the UltraScan PRO, if I change the display of the “spectral data” to a shorter range, or change the nm resolution, does that change the color calculation data in any way? Does this only change the displayed output, or is this also changing the way L*, a*, b* color values are calculated?

The USPRO reports spectral data at 5 nm intervals for an extended wavelength range of 350 nm to 1050 nm as a normal measurement.

Spectral data for the full CIE visible range of 360 nm to 780 nm in 5 nm intervals is used for the calculation of color values per CIE protocols as described in ASTM, ISO and JIS industrial color methods. The extended wavelength below 360 nm and above 780 nm is available for product characterization but is not used in the calculation of color values.

If you change the wavelength range or interval in the Spectral Data or Spectral Plot views for a different range or reporting interval, it only affects the display of those views you changed, not the calculation of color values which uses the underlying measurement data above.