Table of Contents
- 1 What is a dead weight tester used for?
- 2 How do you use a dead weight tester?
- 3 Why the dead weight tester is such a good pressure reference?
- 4 What precautions should be taken while calibrating with dead weight tester?
- 5 How do you calibrate a dead weight tester?
- 6 What is considered dead weight?
- 7 What factors affect the accuracy of dead weight tester?
- 8 What can you do with a dead weight tester?
- 9 Why is a dead weight tester called a primary reference standard?
What is a dead weight tester used for?
A deadweight tester is a calibration standard that uses the principle of a pressure balance to calibrate pressure measuring instruments. Deadweight testers use calibrated weights to apply known pressures to a device under test for a simple and cost-effective solution that covers a wide range of pressure calibrations.
How do you use a dead weight tester?
It works by loading the primary piston (of cross sectional area A), with the amount of weight (W) that corresponds to the desired calibration pressure (P = W/A). The pumping piston then pressurizes the whole system by pressing more fluid into the reservoir cylinder.
Why the dead weight tester is such a good pressure reference?
A dead weight tester is often called a primary reference standard because it is considered to produce the most accurate results because the mass of the weights and the area of the piston cylinder are known to a very high accuracy.
Which oil is used in dead weight tester?
DH▪Budenberg provide hydraulic mineral oil in 500 ml containers labelled “ISO VG 22” for use up to 2600 bar in dead-weight testers. It is no more hazardous than other common lubricating oils.
Why is it called dead weight?
Dead weight testers are named so because they utilize dead weights in determination of pressures operating in a closed and compressed fluid system. Each weight is stamped with the equivalent amount of force that will be exerted on a predetermined area of piston cylinder arrangement by using that weight.
What precautions should be taken while calibrating with dead weight tester?
Ensure that the test gauge is reading zero, if not correct the zero error and ensure that the gauge is reading zero before proceeding with the calibration exercise. Step 3: Turn the handle of the adjusting piston or screw pump to ensure that the weight and piston are supported freely by oil.
How do you calibrate a dead weight tester?
How to perform the test
- The pressure gauge should be mounted in the same orientation (vertical or horizontal) as in the process.
- Measurement points should be distributed uniformly over the calibration range.
- Calibrated weights are placed on the instrument corresponding to the measurement points.
What is considered dead weight?
1. The weight of someone who is sleeping, unconscious, or intentionally limp, making them more difficult to move or carry than they would be otherwise.
Why does dead weight feel heavier?
People feel heavier when they are unconscious because they their body has gone limp. This limpness means that the person’s weight is imbalanced and constantly shifting. So, one would have to put in more effort to hold person in such a way that their weight remain equally balanced.
Is deadweight actually heavier?
When someone is “dead” or “unconscious”, the person does appear to weigh more, but in reality, this apparent weight change has very little to do with the presence of life or consciousness, and much more to do with the placement of weight.
What factors affect the accuracy of dead weight tester?
Like most measurement systems there are many factors that affect your accuracy. Potentially, the largest factor affecting accuracy in a deadweight tester is local gravity. Gravity varies slightly from one location to another (see map). This has an impact on the nominal pressure increments of a deadweight tester.
What can you do with a dead weight tester?
When properly configured and operated, the fluid pressure generated by a deadweight tester will be exactly what it should be, and this precisely-known pressure may then be used to test the accuracy of any pressure-sensing instrument.
Why is a dead weight tester called a primary reference standard?
A dead weight tester is often called a primary reference standard because it is considered to produce the most accurate results because the mass of the weights and the area of the piston cylinder are known to a very high accuracy.
What should the pressure of a dead weight test be?
The use of high quality materials result in small uncertainties of measurement and excellent long term stability. Dead weight testers can measure pressures of up to 10,000 bar, attaining accuracies of between 0.005% and 0.1% although most applications lie within 1 – 2500 bar.