# What is Calibration: Definition and 95 Discussions

In measurement technology and metrology, calibration is the comparison of measurement values delivered by a device under test with those of a calibration standard of known accuracy. Such a standard could be another measurement device of known accuracy, a device generating the quantity to be measured such as a voltage, a sound tone, or a physical artifact, such as a meter ruler.
The outcome of the comparison can result in one of the following:

no significant error being noted on the device under test
an adjustment made to correct the error to an acceptable levelStrictly speaking, the term "calibration" means just the act of comparison and does not include any subsequent adjustment.
The calibration standard is normally traceable to a national or international standard held by a metrology body.

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1. ### I James Webb telescope calibration

I understand that many of the extreme distance objects were incorrectly calibrated for their distance and subsequent age. I have been trying to track down the related articles detailing the error with the applicable mathematics. If anyone knows where I can get the related calibration papers it...

I've wanted to check the accuracy of my Blood Pressure Monitor (BPM) (an automated Omron unit), and finally found this old (2016) thread on another site (linked below). Prior to this, I only found the less helpful 'compare the reading to your Doctor's office' (BP varies with every reading, not...
3. ### A Standard radionuclides used in energy detector calibration

In using scintillator or germanium energy sensors, certain radionuclides representing some definite line energies are used to calibrate the sensors. What technique or method is used to measure or determine the energies of these standards.
4. ### Engineering DC Generator calibration plot

Summary:: Hello Got the following plot (please see below), and am trying to figure out the phenomena behind it (plot behaviour) What do you guys think? It's a DC Generator to be calibrated. On the x axis: the ratio between the power of the generator / nominal power of the generator, while on...
5. ### When does the calibration uncertainty contribute to a measurement uncertainty?

Often a calibration certificate for an instrument has the error found during the calibration as well as the uncertainty associated calibration itself. I'm reasearching uncertainty calculations using the GUM 1995 method and I haven't found one yet that includes the uncertainty of the calibration...
6. ### Calibration of a Meter Stick

I'm trying to find literature on different methods to calibrate a meter stick. Does anyone know any good sources I could use?
7. ### Sodium Vapor Lamps (low pressure) for spectral calibration and diffraction work

Just curious if anyone out there is using the old low pressure sodium vapor lamps for spectral calibration and diffraction work. I was surprised that I do not see any bench ready laboratory lamps from the usual vendors. I understand that the last manufacturer of the low pressure bulbs, Philips...
8. ### Is this officer checking his radar gun calibration incorrectly?

I was watching "Northwest Law" last night (a TV show that follows Fish & Game Rangers in the Northwest), and when I saw an officer checking the calibration of their radar gun before using it on an ATV trail, I was very confused by it. He held it so that the tuning fork vibrated orthogonally to...
9. ### Can the Method of Least Squares be Used for Non-Linear Data?

Many years ago I was given a problem involving the calibration of sets of weights. Each of two sets consisted of weights of 1.0 kg, 500.0 g, 300 g, 200 g, and 100 g. The two 1.0 kg weights were calibrated by the international agency in France and I was permitted to assume that their masses...
10. ### I Calibration of axis for Oragami folds

This problem came to existence as an attempt to justify a very common operation that an origami folder is often faced with. Broadly speaking, when one folds a model, it is almost always necessary to divide the paper into some segments. The statement that has to be proven: given the proportion...
11. ### I Calibration of Minkowski Diagram: Explaining Invariance of S^2

Can anyone please illustrate highlighted part? Can anyone please explain me how invariance of s^2 is useful in characterization of events? I didn't understand the highlighted part i.e. how to determine velocity of S' relative to S?
12. ### Standard addition concentration positive

I am computing limit of detection of zinc of an electrolyte. Using standard additions method, I have obtained positive x intercepts for 6/8 samples all very close to zero. Positive x-intercepts imply final concentration values to be negative. if x-intercept taken to be zero, the concentration...
13. ### Calibrating Argon Spectrum with MicroLab Spectrometer Model 141

Hi, I need some help to calibrate argon spectrum. I have a MicroLab Spectrometer (Model 141) to obtain spectral images of argon plasma. To calibrate the spectral images, I need a reference of known wavelength. Usually, a discharge tube is used to obtain the reference spectrum. However, I...
14. ### Checking pH meter calibration HCL >37%

Hi, I've calibrated our pH meter using 4.01 and 7.01 buffer solution, but I'm not sure if the probe has dried out at some point. So I want to check the calibration, I have some HCl > 37% that I can use. Just a quick question, since pH is on a log scale so I have to make solutions every ten...
15. ### Efficient Venturi Tube Calibration for Digital Peak Flowmeters | Thesis Design

I've designed a venturi tube for my thesis ( Design of a digital peak flowmeter). I was wondering if there was a way to calibrate the flowrate, without using a measured flowrate producing device. The current error is about 12.3%. Theoretical 610L/min vs experimental 535L/min.
16. ### Calibrating a rain gauge (problem interpreting question)

Homework Statement We wish to make a precipitation meter shaped like a paraboloid ##z = x^2 + y^2, 0 \leq z \leq 10##. Devise a scale on the z-axis that tells you the amount of precipitation in cm. In other words, at what height ##z = h## is the surface of water in the dish when there has been...
17. ### Need Help to Calibrate Semiconductor Parameter Anlyzer 4156B

Hi, I have been using Semiconductor Parameter Analyzer Agilent 4156B for 1 year. Since a month it is malfuntioning. I am not getting the required IV for my Resistive Random Access Memory (RRAM) devices. To confirm, I checked my devices using some other lab's analyzer which proved that there is...
18. ### Understanding the Role of Calibration in Vapour Pressure Determination

I am doing a lab which involves the determination of vapour pressure of a particular compound by Knudsen Effusion. Like other analytical methods it involves calibration but we are using the know vapour pressure of naphthalene because its in the accepted range. So we have an equation for the...
19. ### Glass electrode voltage calibration and pH analysis.

Hi, I'm stuck on part b) of the question below: Q: In order to perform pH determinations with a glass electrode, the cell potential was measured for threestandard solutions with the following pH values at 25 C: 2.04, 7.05, and 9.20. The cell voltage readout(in mV) for each of the above solutions...
20. ### Can I Create a Calibration Curve Using Only Peak Area Data?

I've just done an ion chromatography experiment and have normalized my data for a known sample which has a known concentration of 10ppm. I know that the first large peak is due to F- ions and so the area of the peak is propositional to the concentration of the ion. Given that I know the area...
21. ### Using calibration data for a beam scale -- How to apply?

Homework Statement I attached the full document, buy I just want to know about : "Using calibration procedure determine: a) Sensitivity (mV/gr) b) Overall instrument error (gr) c) Linearity error %FSO d) Hysteresis error %FSO e) Precision error %FSO" Homework EquationsThe Attempt at a...
22. ### Calibrating RTD Sensors with 3 Instruments: Rajesh's Guide

HI.. This is my first post here. I want calibrate RTD sensors so I am planning to buy Temperature calibrators includes three instruments with individual reference senors for three different set points(-ve, and two positive points). I am planning to calibrate RTD sensor by these three...
23. ### Can temperature affect the mass of water

Hi there guys, I'm conducting an experiment to calculate the mass flow rate of water. Bellow is a copy of the procedure: 1) Weigh the mass in kg of a container 2) Connect a flow meter to a tap (any source) with a pipe and insure the departure pipe goes into a sink 3) Open the tap an increase...
24. ### Gamma spectrometry: Calibration using X-ray emissions

I have just done an efficiency calibration measurement for the HPGe detector of a whole-body counter. Ba-133 and Eu-152 were the calibration nuclides. For a calibration at low energies I thought of using the X-ray emissions of both nuclides as well. However, the result looks quite bad - see the...
25. ### Checking Control Loop Calibration

Homework Statement Homework EquationsThe Attempt at a Solution Process actual at 300 Transmitter range 100 - 420 Output 4 - 20mA Output Actual 15.43mA Conditional output 3.85 PV and SP at 300 Valve position at 30% Anyone can help if I am on a right track? I am not sure how to start...
26. ### Can a Thermometer Be Calibrated Without Using the Formula Provided?

How do we caliberate a thermometer by cross multiplying without using the formula
27. ### Independent calibration of structure and load cell?

I have a load cell which must be placed onto a piece of vehicle structure. In an ideal world I would attach the load cell to the structure and calibrate both together to ensure a very accurate calibration, and that accurate loads are measured. However a problem arises if I need to replace the...
28. ### Calibration cosmic distance scale on age globular clusters

Hi, Could someone enlighten me in this matter? . how the calibration of cosmic distance scale affects the determination of the age of globular star clusters? thanks a lot :)
29. ### Simplest possible light sensor relative calibration

I am looking for way how to do relative calibration of light sensor (PMT). I would appreciate any suggestions or links to sources with description how to do it in very simple (understand also cheap if possible) way. For example. Let say that I have integration sphere with two outpust. I have...
30. ### Help requested for temperature sensor calibration

Hi all, My university did not provide any metrology courses as part of my degree, and our lab experiment sessions are not very hands on, unfortunately. Thus, I am a bit out of my depth. I need to calibrate some temperature sensors as part of my mechanical engineering internship. I have an 8...
31. ### Understanding TEM Calibration Patterns: NiOX vs SiGe Explained

Ok, so we were doing TEM and at the end we were looking at calibration patterns and I'm preparing the presentation and I am writing the intro but I realized I'm not sure why the calibration pattern looks like concentric circles. I believe it is because we are scanning the beam across the sample...
32. ### Is the Light Clock Calibration the Key to Understanding Relativity?

Hello PF. Re. the light clock / train thought experiment. It seems to me that the clock calibration chosen, ( light's mirror to mirror path ), is determining the outcome of the experiment. And that a different calibration would give a different result. e.g. assuming the mirrors are one metre...
33. ### Instrument Calibration Intervals: Self-Calibration Accepted?

Just out of curiosity why is the calibration interval 1yr for lab instruments like DMM, scope etc. Why not 2 years. Also, you use a higher accuracy bench DMM to calibrate a hand held DMM. Instead of getting calibration done by an outside agency, Why not calibrate the handheld DMM...
34. ### Calibration of HF Spectrum Analyzer

Hey guys, Cannot seem to find the answer to my question within the Owners Manual for our high-frequency spectrum analyzer. When performing the 2-port calibration, it gives the option of testing in forward or reverse, which is a function of the test cable's orientation (male or female). Is it...
35. ### Negative values in calibration curve

Hi I just wondering how to report negative values cuased by non-zero intersection. For example, when the absorbance<0.037 in the figure, the concentration would be negative. Thank you!
36. ### Advantage/Purpose of Transmission vs Absorbance in calibration curve

Homework Statement The problem involves a calibration curve which was created and where % T vs concentration was favored for use over the usual Absorbance vs concentration and a question of why would this be used in favor over the latter relationship curve was presented. other details...
37. ### RTD sensors calibration equipment

Hello ! This is my first post on the Physics Forums. I am electronics technician employed in mass spectrometry laboratory at RBI Institute, Zagreb, Croatia. My question is related to calibration of RTD sensors, which I must do in another lab or division, and since I developed prototype of...
38. ### Help Na-22 Beta calibration

Hello, I am working on a project that is attempting to use GM tubes to detect low levels of radiation emitted from food or other objects. Currently I am trying to find the efficiency of these tubes to beta and gamma radiation. I wanted to get a pure beta and pure gamma source but I was...
39. ### Basic statistics calibration question

Hi guys, My friend was asked the following question in an interview: There are 3 weight scales and a 10kg weight. You weigh the 10kg on each scale 5 times (total of 15 measurements for the 3 scales), each measurement is a bit off the 10kg mark (lets say the first scale shows: 11kg, 9.4kg...
40. ### IR thermometer calibration source

Hi, I currently have a black body calibration source which I use for work. It works great, I can calibrate all the IR thermometers just fine, however it isn't a simple quick "check". The IR thermometers are the ratio type in that they measure two wavelengths and using the ratio it can work out...
41. ### Why don't handheld devices have screen calibration settings?

I mean i love having the screen set to perfect calibration like the iphone, but why don't we have tvs like that? It would be nice to not have to set anything on a tv and have a perfect picture quality. Do you think that will ever happen? Vice versa, do you think handheld devices will have screen...
42. ### Does Leaving Torque Wrenches at High Settings Affect Calibration Accuracy?

Hi, I hope this is in the correct section, please feel free to move it or advise me to move if it's in the incorrect section. I work as an aerospace engineer and a sideline of what i do is to maintain the torque wrenches we use on the equipment. We have a set schedule for maintenance every...
43. ### Calibration curve (absorbance)

Homework Statement Hi. I have a table where there is an absorbance for a 0.00 concentration (blank). I now that I have to substract that value to to each of the other absorbances that I have, but my question is... Do I have to graph (concentration 0.00, absorbance 0.00) in the calibration...
44. ### Calibration of a Thermocouple and the Seebeck Effect

Homework Statement We were asked to calibrate a J type thermocouple. In order to do that our reference junction was kept at 1°C while in the other junction the temperatures were raised from 22°C to 93°C (we registered the voltage every 2°C) then we plotted the data in a graph with the...
45. ### Spectroscopy: Determining Phenol Concentration using Calibration curve

Hello, My problem is as follows: The lab I am working on requires the construction of a calibration curve from the measured absorbance of samples of known phenol concentration to intrapolate the phenol concentration of two unknown samples. I have constructed the calibration curve and...
46. ### AIPS: flagging bad data, calibration, etc

i am trying to learn AIPS in preparation to doing research in radio astronomy. I know the basics of radio astronomy and that AIPS is used to reduce data and remove errors from images due to atmospheric disturbances, but I don't really know what kind of errors in the data I should be looking...
47. ### Supernova 1a Distance Calibration & Implications for H_0

A new paper on supernova 1a distance calibration 'The luminosity of supernovae of type Ia from TRGB distances and the value of H_0' - http://arxiv.org/abs/1208.5054 - brings into question the value of Ho. The authors derive a value of H0 = 63.7, considerably below the present accepted value of...
48. ### What is the purpose of calibrating a faraday cup in electronic systems?

what does calibrating a faraday cup mean??
49. ### Themocouple calibration question

One method I've found is putting the thermocouple in an ice bath, then boiling water and plotting actual temperature vs. measured TC temperature. A linear curve fit is then applied between the two reference points, and used in a DAQ program to 'correct' the TC measurement coming into the DAQ...
50. ### Calibration of gamma-ray spectra

So I have an assignment due in tomorrow night that I've been working on recently and I find myself with a question. Because our software was playing up it wouldn't give us the correct algebraic relation to calibrate our results, so I've had to manually do this. From the three sources we were...