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03/12/20

Customers often measure the same laser with 2 different Ophir sensors, both of which are specified to be within calibration. Let’s say that both of the sensors are specified to have a calibration uncertainty of ±3%. Do I expect the difference in reading between them to be less than 3%? On the first thought, this is what one might expect. However this is not necessarily so.
 
First of all, when we specify a calibration accuracy of ±3%, we are talking about a 2 sigma uncertainty, i.e. the readings of various sensors will be within a bell curve with 95% of all sensors reading within 3% of absolute correct calibration and 5% reading outside this accuracy. Thus there is a small chance that the meter will not be reading within 3% of absolute accuracy.
 
A more important reason is that the two sensors’ calibration error may be in two different directions and thus show a larger discrepancy between them than 3%. Say one sensor has been calibrated and reads 2.5% above absolute calibration and the other 2.5% lower than absolute calibration. Both of the sensors are within the specified ±3% absolute calibration but they will still read 5% differently from each other.
 
If we do statistical analysis, the analysis will show that there is in fact a probability of >16% that two correctly calibrated sensors will differ in reading from each other by more than 3% and a probability of over 6% that the sensors will differ in reading between each other by more than 4%.

05/08/17

Our recalibration process is to not automatically upgrade the firmware in meters when they are sent in for recalibration, unless specifically requested to upgrade it. The reason for this is that we support many companies, such as medical companies, that have equipment validation processes that don’t allow changing the firmware version from the currently validated version. If you do want the latest firmware version installed, we will do that at no additional charge (for meters which are upgraded electronically) if it is specifically requested on the RMA request checklist form. For older meters (such as the Nova) that are upgraded through changing the EEPROM, a nominal fee is added, if firmware upgrade is requested. Note; upgrading the firmware does not affect the calibration.

06/09/14

Technically it could be replaced, but it is not just a matter of replacing the filter. Since the PD300 is a "calibrated" sensor it requires that the filter also be "calibrated". Especially since the PD300 response varies with wavelength, it requires that both the PD300 and the filter be calibrated over the entire spectral range with a monochromator. Because of the cost to calibrate the replacement filter with the PD300 sensor, we recommend purchasing a new PD300 sensor when a replacement filter is needed.

Calibration of Ophir Terahertz Sensors

Terahertz (THz) applications - till recently mainly still in the R&D phase - are beginning to emerge into the light of the commercial and...
11/18/19

Special Calibration

Ophir offers a "special calibration" service so the customer can be provided with higher calibration accuracy than the standard catalog...
05/02/18

Expanded ISO Accreditations

By Kristen Winterton, Calibration TechnicianAt Ophir-Spiricon we pride ourselves on providing quality in...
02/01/16

Calibration Capability at Ophir

Calibration is perhaps the most important of our products. We have a complete line of calibration lasers so that we can always calibrate at or near the customer...
05/19/14

Need more help? Ask one of our experts! and we'll contact you as soon as possible
 

03/12/20

Customers often measure the same laser with 2 different Ophir sensors, both of which are specified to be within calibration. Let’s say that both of the sensors are specified to have a calibration uncertainty of ±3%. Do I expect the difference in reading between them to be less than 3%? On the first thought, this is what one might expect. However this is not necessarily so.
 
First of all, when we specify a calibration accuracy of ±3%, we are talking about a 2 sigma uncertainty, i.e. the readings of various sensors will be within a bell curve with 95% of all sensors reading within 3% of absolute correct calibration and 5% reading outside this accuracy. Thus there is a small chance that the meter will not be reading within 3% of absolute accuracy.
 
A more important reason is that the two sensors’ calibration error may be in two different directions and thus show a larger discrepancy between them than 3%. Say one sensor has been calibrated and reads 2.5% above absolute calibration and the other 2.5% lower than absolute calibration. Both of the sensors are within the specified ±3% absolute calibration but they will still read 5% differently from each other.
 
If we do statistical analysis, the analysis will show that there is in fact a probability of >16% that two correctly calibrated sensors will differ in reading from each other by more than 3% and a probability of over 6% that the sensors will differ in reading between each other by more than 4%.

Calibration of Ophir Terahertz Sensors

Terahertz (THz) applications - till recently mainly still in the R&D phase - are beginning to emerge into the light of the commercial and...
11/18/19

Special Calibration

Ophir offers a "special calibration" service so the customer can be provided with higher calibration accuracy than the standard catalog...
05/02/18
05/08/17

Our recalibration process is to not automatically upgrade the firmware in meters when they are sent in for recalibration, unless specifically requested to upgrade it. The reason for this is that we support many companies, such as medical companies, that have equipment validation processes that don’t allow changing the firmware version from the currently validated version. If you do want the latest firmware version installed, we will do that at no additional charge (for meters which are upgraded electronically) if it is specifically requested on the RMA request checklist form. For older meters (such as the Nova) that are upgraded through changing the EEPROM, a nominal fee is added, if firmware upgrade is requested. Note; upgrading the firmware does not affect the calibration.

Expanded ISO Accreditations

By Kristen Winterton, Calibration TechnicianAt Ophir-Spiricon we pride ourselves on providing quality in...
02/01/16
06/09/14

Technically it could be replaced, but it is not just a matter of replacing the filter. Since the PD300 is a "calibrated" sensor it requires that the filter also be "calibrated". Especially since the PD300 response varies with wavelength, it requires that both the PD300 and the filter be calibrated over the entire spectral range with a monochromator. Because of the cost to calibrate the replacement filter with the PD300 sensor, we recommend purchasing a new PD300 sensor when a replacement filter is needed.

Calibration Capability at Ophir

Calibration is perhaps the most important of our products. We have a complete line of calibration lasers so that we can always calibrate at or near the customer...
05/19/14