Questions tagged [measurements]

Measurements, instrumentation, calibration and metrology.

41 questions with no upvoted or accepted answers
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2answers
132 views

In what cases are the roughness values Rt and Ra used?

Roughness measurement instruments output those two values, where Rt is the distance between the top of the highest peak and the bottom of the lowest valley, and Ra is the average distance of every ...
2
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0answers
51 views

How can I calculate the smallest voltage a given adc can read?

I have a project where I'd need to measure small voltage (0.05 mV) output of a wheatstone bridge with an arduino mini pro. Based on my previous question most probably it can't be done with its ...
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0answers
27 views

How to measure the inertia of an object using a motor

first time on this board even if I've been lurking for a while. I'm a tennis racquet technician and, for the sake of saving some money and just for the fun of it, I'm trying to build a machine that ...
2
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0answers
61 views

Maintaining constant speed of a CVT engine during a slope

I am not sure if this question is related to this community. But nevertheless. I work on CVT engines, I had a new idea of modifying my controller during a slope or a gradient on the road so that the ...
2
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0answers
38 views

Finding liquid viscosity

I'd like to calculate the viscosity of a liquid in a container systematically (and feed the results back to a computer). I only have basic knowledge of physics and mechanics. I think that a motor ...
2
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0answers
56 views

Measuring Helix Angle

What is the best way to measure the helix angle of a helical cut gear? I have a sun gear from a planetary set that I would like to have custom made but I'm not sure the best way to get the helix angle,...
2
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0answers
32 views

Measuring moisture in walls remotely

There exist devices (e.g. Bosch PTD 1) which measure the temperature and humidity/moisture of the room and remotely (without contact) of a wall they are pointed at. I understand that you can measure ...
2
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0answers
52 views

Ambient helium level monitoring

I am looking for a solution to monitor and log ambient He levels down to 50-100ppm. The detector is meant to be installed in an experimental hall where a large number of Photo Multiplier Tubes are ...
2
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0answers
815 views

Hydrogen in submarines: “keep below 8%” rule of thumb?

In the book "Against the Tide: Rickover's Leadership Principles and the Rise of the Nuclear Navy", Rear Admiral Dave Oliver (Ret.) narrates some of his experiences in the USS George Washington Carver, ...
2
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0answers
24 views

Decission between several position switches and one continuos position signal for controling rotating conveyor

We plan a conveyor that will dump something into containers. A level gauge on the tip of the container will measure the heap below. The conveyor is placed on a turntable and will e rotated ...
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0answers
24 views

Finding force distribution using accelerometer data

The team I'm currently working for is trying to compare bushings with different durometer ratings in the front suspension using single axis(z) accelerometer data during curb impacts. The current ...
1
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1answer
71 views

BJT Output Characteristics Question

Ok, so I am pretty confused at the moment with a question that I have been given to work out by my lecturer and was wondering if I could get some guidance with it. I will attach images of the question ...
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0answers
16 views

how do you calculate viscocity from torque arm load cell measurements?

I have a piece of company developed equipment that uses a pot mounted on a rotating base plate with a 0.15m torque arm and load cell, a mixing paddle is used to stir the mixture while the controller ...
1
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0answers
123 views

Which imperial units of measurement use vulgar (simple) fraction numbers?

All values of metric units are expressed in decimal or scientific notation. Some imperial units, use fraction numbers as primary notation (3/4" for 0.75 inch). As far as i know, only inch and foot ...
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0answers
46 views

How much does loading a load cell in other directions than the direction it was designed for effect the readings?

I am looking into using this TAL230B miniature type load cell to measure forces in x and y direction. The normal sensor loading is displayed in image 1. What is the effect of loading them as in image ...
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0answers
35 views

Strange offset on oscilloscope channel

I've a Rigol DS2072A. It works great except for an offset problem that I noticed the past few days. Channel 2 always shows a DC offset. This is independent of any settings such as channel coupling, ...
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0answers
368 views

Detergency and dispersancy

Abstract:The detergency property in oil comes from a chemical additive called detergent which has a property of preventing the deposition of carbon deposits and wash it away. There is also this ...
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0answers
53 views

Is there a 5% range CO sensor with a response rate higher than 1Hz?

I'm building a portable emission analyser which measures emissions from a tailpipe, to aid in troubleshooting and tuning an engine. For this, I need a $\text{CO}_{2}$ , a $\text{CO}$, and an $\text{O}...
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0answers
44 views

How to convert permeation units to molecules/second?

How do I convert $\dfrac{\text{cm}^3\cdot\text{mm}}{\text{m}^2 \cdot \text{day} \cdot \text{atm}}$ for permeation of gas through EVOH to molecules of gas permeating per second as a function of ...
0
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1answer
48 views

Tolerances in a pin-hole assembly

Hi guys, can someone explain how to do this question? This question is under Geometric Dimensioning and Tolerances and I am clueless on how to tackle problem like this. EDIT This is the explanation ...
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0answers
74 views

How to use Spectroid app to measure low frequency vibrations?

Need to measure how low frequency (vibration) changes when going through different materials. The only possible way found is by using Spectroid app. However, have no idea of what settings to set up. ...
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0answers
22 views

Is there an instrument that can measure thickness of an object through strain?

So basically, I am doing a project to design a measurement tool for measuring the different layers of the quartz crucible used in the semiconductor industry. Since the crucibles undergo some ...
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0answers
26 views

Vibration measurement of rotating blade

In a vibration measurement of a rotating blade, I have the following information. The vibration signal is measured using an ICP accelerometer which has the following specification Measurement range: ...
0
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0answers
26 views

How does the number of cycles for averaging in a lock-in amplifier relate to low-pass filtering and where do I set it?

Please forgive me if I ask too many questions at once or I am too much of a rookie. I want to understand the working-principle of lock-in amplifiers (LIAs). I understood the calculation that yields ...
0
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1answer
63 views

Can I use loadcell for vibrating force measurement?

Is it possible to use a load cell to measure a force that is vibrating? The idea is to measure that force that is getting into the load cell in a sweep of frequencies and vibration is NOT a noise. ...
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0answers
20 views

Estimating trunk rotation using frontal and sagittal views

I am doing an experiment regarding elbow flexion's effect on peak sprinting velocity and we want to measure trunk rotation and shoulder rotation during our trials. We don't have an overhead camera so ...
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0answers
24 views

How to measure and create PVT diagram

We have all seen PVT diagrams. From my understanding one should measure pressure, volume and temperature on or near the outside of the system. Volume: maybe by displacing water initially and then ...
0
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0answers
25 views

How to design a method to estimate vx=speed in direction of swimming

We have a body that goes underwater (let's say a whale) with magnetometer and accelerometer data. I also have GPS, date, depth, pressure and temperature data. I want to know if there is any simple way ...
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0answers
33 views

What is dead beat reading?

I was reading about characteristic of a comparator. It states Comparator indicator device should be such that the readings are obtained in least possible time and for this magnification system should ...
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0answers
31 views

Why is there no widely-used standardized unit for indentation hardness?

The last hundred years have seen a great degree of standardization of units, and the expression of units of measurement in standardized, instrument-agnostic, objective terms, often in the SI units. ...
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1answer
82 views

off-scale torque measured - what is my torque arm?

I have assembled a benchtop torque measurement stand for evaluating electric motor and controller efficiency. The motor is 49kV , 5kW brushless outrunner. Input power reading is taken from motor ...
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5answers
69 views

How can I get the horizon or vertical length of the uneven object?

Just like the picture shown I want to have the length from the front end to the windshield in horizon, and want to have the length from the lowest point to the highest point of the hood in vertical. ...
0
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1answer
112 views

Typical range of a small hole gauge.

I want to get this out there. What is a typical and common range of a small hole gauge?
0
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1answer
51 views

Can foil strain gauges measure strain normal to the plane of the sensor?

I'm wondering if anyone in the community has experience with foil strain gauges used to measure strain components that are normal to the plane of the sensor? If the strain gauge were pressed between ...
0
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1answer
102 views

Automated valve for testing module

I work frequently with materials sensitive to oxygen and moisture, within a glove box. However, there are frequently times I want to move these samples from the glove box to a scanning electron ...
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0answers
66 views

Safety factor for pressurized container at 10 ATM

There is no secondary containment to hold any potential shrapnel. How would this change the safety factor that is standard at 2.5? The consequences of this container exploding would be quite extreme ...
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0answers
45 views

What type of acturator with motor to choice for measurement with step = 0,25 μm?

I need to select some linear acturator or build it. I see it as: On green platform there is pink device. This device must be measured. For this purpose we need to choose linear acturator with ...
0
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1answer
311 views

How can I measure the coefficients of friction of pulleys?

I have to study several industrial pulleys made for lifting heavy weights. It is important to select one which has a low coefficient of friction because the system is based in a hoist and several ...
-1
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1answer
40 views

What are the simplest available methods for monitoring pressure and airflow in a 22mm diameter pipe?

In the emergency case that more than one person must share a mechanical ventilator, the medical professionals lose per-patient monitoring of pressure and airflow. To that end, what are the simplest ...
-1
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1answer
36 views

Way to digitally measure volume of air inhaled by lungs?

I was interested in this as a fun project. To be able to get the volume of air inhaled by a person has some cool applications I can think of. I was thinking of a modified anemometer of sorts fitted ...
-1
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1answer
200 views

Must MSA (Measurement System Analysis) be re-performed after annual instrument calibration?

I'm working in an automotive company that must follow IATF (International Automotive Task Force) requirements. I administrate a test-bench that performs RF (radio frequency) tests using an ...