Thermometer Definition and 81 Threads

Here is the table As far as I can tell what we have here are four constant-volume thermometers (each column represents a thermometer). These thermometers work by having a certain constant volume of some specific gas in a bulb. We immerse the bulb in whatever temperature we would like to measure...

I posted another question about a thermodynamic system with three coordinates, namely, that of a metallic wire. We can describe that system with temperature, wire tension, and wire length. The result derived in that question was that the partial derivative of wire tension relative to absolute...

a. The resistance thermometer bridge circuit shown in FIGURE 1 has a designed maximum temperature of 200°C, ignoring the effects of connecting wire resistance. If the connecting loop is 250 m determine the smallest gauge (swg) of copper wire which must be used if the indicated maximum...

I am able to solve part (a) using the relationship ##\frac {P_1} {T_1} = \frac {P_2} {T_1}##, where ##T_1 = 273.16## since its the triple point of water and ##T_2 =T_s## ##(T_s = ## melting point of sulphur). I use the two readings for thermometer A to get ##P_1## and ##P_2## as mentioned in the...

Question description: How could we increase the sensitivity of a liquid-in-glass thermometer such as the mercury thermometer? What is the basic principle for each method ? There are some options: 1.Increase the size of the bulb. 2. Use thinner glass wall outside the capillary tube. 3. Decrease...

Hi, I didn't understand the maths involved in the below article in regard to temperature and ideal gas thermometer. If any member knows it, may reply me. If triple point of water is fixed at 273.16 K, and experiments show that freezing point of air-saturated water is 273.15 K at 1 atm...

Hi, Why the alcohol thermometer is less precise than the mercury one? If I remember correctly, it is because the thermal expansion coefficient of alcohol is not constant, but I am not sure. Thank you for your time. Regards, ORF

I am thinking to make a strange thermometer, based on the thermal expansion of a small aluminium-like rod/cylinder. I would attach one end of this aluminium rod to a vertical ceramic wall, and the other side would push against a piezoresistive material. I would then measure the resistance of...

Isn't it both use the same exact principle? An infrared thermometer versus a thermal imager? Why is it that the thermal imager is not for body temperature (as indicated below) while the infrared thermometer is for body temperature. I think they both scan the same blackbody of the physical body.

Hi, I found this question/s online and I was wondering if somebody was able to explain the answer given, specifically the first bit that says R1/(R1+R2) = R4/(R3+R4) (is this something to do with an equivalent resistor to replace the two in series on each side? But why are R1 and R4 the...

Hi All, Really struggling to get my head around what I'm doing wrong - every time my answer of wire diameter comes out too small for what's included in the table of SWG. I must be doing something wrong somewhere - my attempt is below. Any help is very much appreciated.

Summary: 1.In the context of calibrating a scale to correlate volume change with temperature, my book states: "Since all substances change dimensions with temperature, an absolute reference for expansion is not available." What do they mean by an absolute reference in this instance? My...

What is the difference in temperature with different thermometers for the same object? Thanks !

So, as far as I understand IR thermometer works by measuring light irradiance coming from an object (in the IR spectrum) and then calculating the object temperature using Stefan's law. Since the irradiance falls like 1/r2 with distance, I am wondering how it takes distance into consideration...

Homework Statement A constant volume gas thermometer contains a gas whose equation of state is (p+\frac{a}{V^2_m})(V_m-b)=RT and another, of identical construction, contains a different gas which obeys the ideal gas law, pV_m = RT. The thermometers are calibrated at the ice and steam points...

Why does mercury in a thermometer expands when we increase the temperature but it doesn't go down after cooling? Why does it just stay there?

What are reproducible thermal phenomena that are used to calibrate thermometers?

Homework Statement In the interval between the freezing point (ice point) of water and 700.0deg-C, a platinum resistance thermometer is to be used for interpolating temperatures from 0 °C to the melting point of zinc, 692.666 K. The temperature, in Celcius or Centigrade, is given by a formula...

In the constant volume gas thermometer, T (°c)=[P(T)-P(f)]×100/[P(b)-P(f)] (P(T) means gas pressure at T°c P(b) and P(f) for the water's boiling point and freezing point) Is it right?

How do we caliberate a thermometer by cross multiplying without using the formula

Homework Statement The "spirit-in-glass thermometer", invented in Florence, Italy, around 1654, consists of a tube of liquid (the spirit) containing a number of submerged glass spheres with slightly different masses (see the figure below). At sufficiently low temperatures all the spheres float...

Hi, I'm a freshman in college and a beginner in electronics. Does anyone know of a way to use a micro analog thermometer to change the color of a small LED light once it hits a certain temperature. I am looking to make this on an extremely small scale.

Homework Statement A thermometer touches the floor and the other touches a wool carpet lying on the floor. what will the two thermometers show, the same or different temperatures Homework Equations Two materials touching each other the heat moves from the warm to the cold one The Attempt at a...

Homework Statement What is the formula that allows you to find the temperature of any given thermometer that varies its temperature with some property? For example is a pressure of 10mmHg means 0degC, what would the pressure be at 50degC? Homework Equations This is what I'm looking...

Is there a way to determine the temperature outside without using a thermometer? Any formulas I could use?

Hi, Does it make a difference if you use nitrogen gas or oxygen gas or hydrogen gas in the bulb ? Or they all give the same readings given that an arbitrarily chosen constant if found for each ? Many Thanks! :)

I am designing a tyre temp monitoring system for my Final year project and I would like to know if it is possible to somehow modify a infrared phototransistor to be able to measure an objects temperature in a range of -20 - 120 C. Any suggestions would be greatly appreciated.

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...

Hello, I am instructed by my chemistry professor to design an experiment to measure the temperature at which a saturated solution of Sodium Nitrate will begin to boil. If the reagents are pure this temperature will be constant . Can someone tell me why does the lab instructor suggests...

A physics stack question asks why when the air is hotter then your body thermodynamics allows your body to operate as a heat engine as a heat engine must have a sink for waste heat. See question here, http://physics.stackexchange.com/questions/59316/human-as-a-heat-engine Part of the answer is...

Homework Statement Explain why it would not make sense to use a full-size glass thermometer to measure the temperature of a thimbleful of hot water. Homework Equations Concept of thermal equilibrium The Attempt at a Solution When a thermometer is in contact into a thermal system...

Hi everyone, So I'm a bit stuck in my physics lab report. I have to make a correction to the temperature read in the laboratory (ex:155.2C) because our room pressure was 742.1mmHg and not 760mmHg I'm guessing. I've tried researching this for a while now but I can't seem to find an easy...

In some threads around here I have hinted to problems with the use of 'water' isotope ratio's (δ18O, δ2H aka δD) as thermometer of past temperatures. This could become a dense thread, so I'll give the conclusion first: The isotope ratio's in ice cores and other records of meteoric water are...

Hello Guys! I was wondering if anyone can tell me why is it that it doesn't matter what gas we are using in the gas thermometer? Will it still be standardized for calibration if we use different gases? Thanks.

Let me preface this by saying that I know very little of circuitry, signals, etc. I have also Googled/searched the forum for help using keywords that are related to this project but also vague enough that I could not find any useful results. I have a friend interested in how the temperature...

I work in a nano-optics group, and need an IR thermometer with certain specifications. Online I have only come across cooking thermometers and industrial thermometers, so I need help finding one for a physics experimental lab setup. Specifications: - high accuracy, and pin-point surface...

I think that I’m doing this problem correctly, but the answer seems a bit unreasonable. Can someone else check my work? A thermometer has a quartz body within which is sealed a total volume of 0.400cm^{3} of mercury. The stem contains a cylindrical hole with a bore diameter of 0.10mm. How far...

Homework Statement A mercury thermometer contains 7.5 mL of mercury. If the tube of the thermometer has a cross-sectional area of 1.2 mm2, what should the spacing between the °C marks be? (The volume expansion coefficient for mercury is 1.81 x 10-4 °C−1.) Homework Equations ΔV=βV0ΔT...

was just wondering... Do IR thermometers measure the temperature of an object via the intensity or wavelengths of emitted light? I've heard that you can measure the temperature of clouds with them, why doesn't the IR light emitted by the air in between the cloud and the detector confuse...

I am urgently need help about it(title) Radiation thermometer can be categories into how many types ? Is it mainly separate into Infrared Pyrometer and Optical Pyrometer only ?

Homework Statement The pressure in a constant-volume gas ther- mometer is 0.811 atm at 100◦C and 0.5 atm at 0◦C. A) What is the temperature when the pressure is 0.656922 atm? Answer in units of ◦C. B) What is the pressure at 138◦C? Answer in units of atm. Homework Equations...

The time constant of a thermocouple is to be found by exposing it to a step change. Then the thermocouple and a thermometer are exposed to a ramp function and measurements from each are taken simultaneously. The time constant and its uncertainty for the thermometer are to be found. I...

Just a note before I start off, this was the first line on this homework assignment: "If you have not studied this yet you can do this problem after reading about it in your textbook."... I've honestly tried reading about this stuff, but our teacher hasn't even started thermodynamics yet...

How a constant volume gas thermometer works? In "Thermodynamics An Engineering Approach" by Cengal, author says that this type of thermometer is usually filled with Hydrogen or Helium and We use Constant volume gas thermometers for measuring temperatures near absolute zero. Now if volume is...

I was thinking about getting my friend one for his bday. Does anyone play around with these? I was thinking he could use it to perfectly cook meats on the grill or test the temperature of a pan to make pancakes, etc. Are they really useful or just overkill that people never end up using if...

Hi, I am wondering if anyone can advice on which kind of digital thermometer would be most suitable for the following conditions: 1. It should quickly be able to detect a sudden increase in temperature. The actual temperature is not important, only the detection of a sudden change in...

Hi! I was wondering if someone could help me understand how to construct an Electric Thermometer so it shows the right Temperature. I have this text from my Teacher to guide me: The temperature sensor provides an output signal which namely is proportional to the temperature, but the...

I'm looking for an accurate and reasonably priced digital thermometer. Our lab has lots of cheap models that provide precision of 0.1 C but are only accurate to +/- 1 C. I can lump them together in a room and get a range of about 3 C. Some sellers don't even provide the accuracy information on...

You know those hand held laser gun thermometers , I was reading how they work and it says that the material you point it at is emitting infrared photons , ok so does the gun shoot infrared photons at the material and then they bounce back and it measures the change in energy or does it just...

Is there a way that I could create a fire detecting thermometer that would detect a fire if the temperature went above a certain point? For example, if a thermometer went above 200 degrees C this would signal a fire? How would I create this?