Why Does My Weight Scale Give Different Readings

Weight Variation by Latitude refers to the claims that scales have measured masses to weigh up to 0.5% less near the equator compared to the polar areas. It is asserted that this is due to a combination of the centrifugal consequence from the rotation of the earth and the increased mass at the equator.

Upon assessment of the experiments supporting this, it is found that these experiments are conducted with the scale and examination body exposed to the surrounding atmosphere. A scale is calibrated for 1 area and then taken to some other area, uncalibrated.^[1][two] Measures are not taken to isolate the test torso and the measuring device from the influences of the ecology atmosphere. Weight is afflicted past factors other than 'gravity'. Pressure, humidity, and other properties affect scales. It is known that that pressure level is greater at the poles and lesser at the equator.^[3] It is further known that pressure is greater at lower altitudes near sea level and lesser at college altitudes. Humidity likewise has a relationship with the latitudes^[4] and the altitudes, likewise as other interrelated properties such as air viscosity.

Andrew Huszczuk, Ph.D., writes (Archive):

  "Would you take a medication knowing that a chemist's shop used an uncalibrated scale to weigh its ingredients? Would y'all board a aeroplane knowing that the fuel or altitude gauges are not calibrated at frequent intervals?

In these and thousands of other applications scientific bases and rules of metrology must exist obeyed to clinch chaos-free functioning of modern societies. To scrutinize performance of measuring devices a process of calibration must be carried out by means of applying a known standard and getting back a right reading. "

Contents

• 1 Scales Affected past Atmosphere
  • 1.1 Precision Scales
  • 1.two Standardscale
  • 1.3 Industrial Scale Company
  • one.four Bathroom Scales
• 2 Uncalibrated Calibration Migrate
• 3 Not a Legitimate Measuring Device
• 4 Kern Gnome Experiment
  • four.1 Calibration Non Calibrated
  • 4.two Procedure
• five Spring Scale Experiment
• 6 Worldwide Air Pressure Slope
• vii Worldwide Temperature Slope
• 8 Worldwide Humidity Gradient
• 9 Addendum
  • 9.1 Historical Fudging
  • 9.two Time Dilation by Latitude
• 10 See As well

Scales Affected by Atmosphere

Precision Scales

From Drift in Measurements with Analytical Balances (Annal) we read:

  "Pharmaceutical laboratories and bioscience research institutes make extensive use of analytical balances that are highly sensitive. These analytical balances are greatly affected by their environment and as well by the fashion they are installed and handled. "

Ane precision scale manufacture lists many factors (Archive) which can affect a calibration:

Factors That Can Affect Your Scale's Accuracy

  "Differences in air pressure – Scales tin can provide inaccurate measurements if the air pressure from the calibration environment is different than the operating environment. "

If the air pressure from the calibration environment is dissimilar than the operating environment, it will affect the scale. Besides listed on the page are temperature and humidity which can touch the performance of a precision scale.

Standardscale

Standardscale.com says (Archive):

How does the surround touch weighing on a lab balance?

  "The environment surrounding a residuum is vital if you are to maintain the manufacturer's stated performance ratings. Really, the manufacturer doesn't affair in this regard, as a bad environment will adversely touch on whatever balance. There are many influences to consider and to remove, as far as is possible, from the area surrounding the balance. "

Industrial Scale Company

The Industrial Calibration Company tells us (Archive):

Sources of Fault in Weighing Instruments

  "Environmental Factors – A scale's accuracy and precision are highly dependent on the environment in which it is installed. "

Bathroom Scales

Inconsistent scale readings are also readily seen at dwelling in bathroom scales. If left uncalibrated, the reading can vary.

Tin I Trust My Bathroom Scale? (Archive)

  "A dietician who weighed herself xv times over the course of a 24-hour interval constitute that she'd "gained" 7 pounds. "

Uncalibrated Scale Drift

On the topic of uncalibrated scale drift precisionscale.com portrays a 0.five% variance every bit small, and gives it as an example of why calibration is necessary.

https://precisionscale.com/scale-calibration/ (Archive)

Understanding the Importance of Calibration Scale

  "In more complex terms, scale calibration involves the procedure of comparing a known standard, such as a calibration service's certified weights, to the results given by the unit that is being tested (your company's scales). Such a procedure ensures the accuracy of the unit being tested. When your business relies on accuracy of weights to run and operate smoothly and protect profits, calibration of your scales is non negotiable. Information technology is an accented must and volition besides ensure that your business is adhering to manufacture standards and Canadian laws and regulations if y'all use the weights and measurements to calculate truck loads.

Why Is Calibrating Your Business organisation's Scales So Important?

While you may not realize it, your business'due south scales and the accuracy they produce have a directly affect on your company's bottom line. If your scales are off, your profits can be off as well. For case, let's say that your business deals in a very expensive powdered cleaning product. If the product cost is $10 per pound and on average you weigh 1,000 pounds of production per 24-hour interval, the total value of product weighed each mean solar day is $x,000.

At present, permit's say that your scale is out of balance past just 0.5 percent. That discrepancy volition cost you lot approximately $50 per day, or $1,000 a calendar month. Unless your company is in the position to literally throw away $1,000 a month ($12,000 a year), and then it becomes very apparent why scale calibration is a necessity. In fact, keeping these numbers in heed, ane tin actually say that such a service is actually an insurance policy protecting your business's lesser line, rather than simply another routine business expense. "

Non a Legitimate Measuring Device

In the Eu if a scale is not calibrated before use afterwards repositioning then it is non considered to be a legitimate measurement device. From a precision scale manual we encounter:

https://www.soehnle-professional.com/documents/all/406/Manual_9437_EN.pdf (Archive)

Kern Gnome Experiment

The precision calibration manufacturer Kern conducted a public test of the variation of weight by latitude, showing that weight inverse when a resin blended gnome and ane of its precision scales were sent to members of the public at dissimilar latitudes:

Website: http://gnome-experiment.com/ (Annal)

Scale Not Calibrated

The scale was calibrated in Frg so sent to different areas:

https://www.chemistryworld.com/news/gnomadic-experiment/4924.commodity (Annal)

  "Kern the gnome and a Kern and Sohn rest, calibrated at the firm'south laboratory in Balingen, Deutschland, are travelling around the globe to anyone who requests a visit in a specially designed flight case. Gloves and cleaning implements also come along for the ride, and so the mass of the gnome isn't altered by dirt or over enthusiastic cleaning.

Several factors affect the gravitational field at different locations on the Earth, for example the closer Kern gets to the equator, the less he should weigh considering the velocity of the World'southward spin at the equator (1670km/hr) counteracts the force of gravity by upwardly to 0.three%. This weight loss will also be increased by the equatorial bulge that ways Kern would exist further from the center of our planet and gravity is proportional to the inverse square of the distance between two objects. "

Long counterbalance from gnome: The baroque experiment where a garden ornament travels the world to measure gravity (Archive)

  "Kern travels in a reinforced instance containing himself and a Kern EWB 2.4 Scale calibrated co-ordinate to local gravity in Balingen, Germany, to ensure any weight alter he encounters on his travels shows up. "

Procedure

Members of the public were instructed to place the gnome onto the scale and to record their results:

Bound Scale Experiment

The Spring Calibration Experiment shows a like methodology of calibrating in one expanse and taking to another:

http://physicstasks.eu/930/spring-scale-on-the-pole-and-on-the-equator (Archive)

  "We calibrated a bound scale on the North Pole then we moved the scale to the Equator.

Does the spring calibration requite the aforementioned readings every bit on the pole? Give reasons. "

The book Practical calculations for engineers (Archive) describes the same method:

  "Suppose such a spring rest be fabricated and calibrated in London by suspended weights which are mutiples or sub-multiples of the point weight. And then if the rest and the standard pound weights were taken to different latitudes, it would be found that the balance would evidence increasing readings for the aforementioned weight in passing from the equator to the poles. "

Worldwide Air Pressure Slope

The following sources explain that air pressure has a relationship with latitude, beingness lower nigh the equator and greater near the poles:

https://www.pmfias.com/pressure level-belts-pressure level-systems-equatorial-low-sub-tropical-high-sub-polar-low-polar-high/ (Annal)

World Distribution of Sea Level Pressure

  "The atmosphere exerts a pressure of 1034 gm per foursquare cm at sea level. This amount of pressure is exerted by the atmosphere at sea level on all animals, plants, rocks, etc.

Near the equator the sea level pressure is depression and the expanse is known as equatorial low. Along 30° N and 30° S are found the loftier-force per unit area areas known as the subtropical highs. Further pole wards along 60° N and threescore° S, the low-pressure belts are termed as the sub polar lows. Nigh the poles the force per unit area is high and it is known as the polar loftier.  "

and farther down:

  "Polar High Pressure level Chugalug

- The polar highs are small in area and extend effectually the poles. - They prevarication around poles between eighty – 90° Due north and Southward latitudes.

Formation

- The air from sub-polar low pressure belts after saturation becomes dry. This dry air becomes common cold while moving towards poles through upper troposphere. - The common cold air (heavy) on reaching poles subsides creating a high pressure belt at the surface of earth.  "

https://en.wikipedia.org/wiki/Polar_High

  "Polar High

The polar highs are areas of high atmospheric pressure around the north and south poles; the north polar high being the stronger one because land gains and loses heat more effectively than sea. The cold temperatures in the polar regions cause air to descend to create the loftier force per unit area (a process chosen subsidence), just equally the warm temperatures effectually the equator cause air to rise to create the low pressure intertropical convergence zone. "

Worldwide Temperature Slope

At that place is also a world-broad temperature gradient, which may have a direct or indirect relationship on variables of the temper to affect atmospheric buoyancy.

https://www.earthonlinemedia.com/ebooks/tpe_3e/temperature/explaining_global_patterns_temperature.html

Worldwide Humidity Gradient

Humidity, like temperature and pressure, has a relationship with the equator besides:

https://en.wikipedia.org/wiki/Humidity#Climate

  "The most humid cities on earth are by and large located closer to the equator, almost littoral regions. Cities in South and Southeast Asia are amongst the most humid. Kuala Lumpur, Manila, Jakarta, and Singapore have very high humidity all year round because of their proximity to water bodies and the equator and ofttimes clouded weather. "

Addendum

When ane examines the properties of the air they will find that other elements too are related to force per unit area, temperature, and humidity; such as air viscosity and thermal diffusivity -- all of which may affect the operation of scales complex means. If a scale is affected by any of that and so those factors should exist excluded, ideally in a vacuum sleeping room experiment which demonstrates the matter empirically, contained of any assumption most the atmosphere. Merely claiming or asserting that there are no factors that bear on the device is insufficient. Nevertheless, a search for examples of this experiment conducted in a vaccum chamber finds none.

Any singular assessment appears insufficient. It is due to the complex nature of the air that scale manufacturers and metrologists recommend calibrating often, whether a scale is indoors or outdoors. A visitor'due south failure to calibrate its scales in certain fields can result in fines and fifty-fifty legal activity. Adopting this basic and reasonable level of scrutiny, an experiment which is based on bringing uncalibrated scales to different environments then looking for differences of a fraction of one percent of a body'southward weight must only be questioned for validity.

Historical Fudging

Of interest, upon reviewing the history of weight changes by latitude we find that the nature of the Earth was modified considering the theory did not meet the data. This is the origin of the flattening of the poles.

From Voltaire nosotros see (Archive):

  "The celebrated Huygens, by computing centrifugal forces, had proved that the consequent diminution of weight on the surface of a sphere was not keen enough to explicate the phenomenon, and that therefore the globe must exist a spheroid flattened at the poles. "

Hence, the theory was changed to fit the event, giving u.s. a circular world with flattened poles. However logical a bulging equator is in concept, the power to alter a theory to see a desired result exists as a fudge factor. Had the results been any more or less dissimilar, the theory or associated theories would accept been changed to fit those results, either past jutting out the equator more or less to fit the data or by looking for other elements to modify.

Time Dilation by Latitude

In contradiction to an uncontrolled three hundred year quondam practice of bringing weighing devices to dissimilar environments and adapting the theory to fit the results, other situations involving devices which are non afflicted past atmosphere do non bear witness changes by latitude. See: Time Dilation past Latitude

Run across Also

Change past Latitude Topics

• Fourth dimension Dilation past Latitude - Time does not dilate as predicted due to the rotation of Earth

Apartment Earth Gravity Topics

• Universal Acceleration - The Universal Accelerator Main Page
• Equivalence Principle - Gravity behaves as if the Globe is accelerating upwards
• Evidence for Universal Acceleration - Experiments and groundwork foundation showing that Earth is accelerating upwards
• Variations in Gravity - Various experiments have failed to find variations in gravity or violations of the Equivalence Principle
• Gravitational Fourth dimension Dilation - Time dilates in accord with the uniform prediction of the Equivalence Principal to various heights

Round Earth Gravity Topics

• Weight Variation by Latitude - An uncontrolled weight alter experiment which is not performed in a vaccum sleeping room
• Cavendish Experiment - An inconsistent brusque range allure experiment
• Gravimetry - Gravimeters are described to be seismometers by mainstream sources
• Isostasy - The mass attraction of mountains and continents does non carry in accordance with 'gravity'

Why Does My Weight Scale Give Different Readings

Source: https://wiki.tfes.org/Weight_Variation_by_Latitude

Share this post