Manometer fluid.?

Question

What is the pink dye in manometer fluid?

Answer 1

It could be a number of chemicals. Historically, it was mercury, but today's gauge's tend to be more environmentally friendly. Mercury is appears red.

Answer 2

Hydrostatic gauges (such as the mercury column manometer) compare pressure to the hydrostatic force per unit area at the base of a column of fluid. Hydrostatic gauge measurements are independent of the type of gas being measured, and can be designed to have a very linear calibration. They have poor dynamic response.

Piston

Piston-type gauges counterbalance the pressure of a fluid with a solid weight or a spring. For example dead-weight testers used for calibration and Tire-pressure gauges.

Liquid column



The difference in fluid height in a liquid column manometer is proportional to the pressure difference. Liquid column gauges consist of a vertical column of liquid in a tube whose ends are exposed to different pressures. The column will rise or fall until its weight is in equilibrium with the pressure differential between the two ends of the tube. A very simple version is a U-shaped tube half-full of liquid, one side of which is connected to the region of interest whilst the reference pressure (which might be the atmospheric pressure or a vacuum) is applied to the other. The difference in liquid level represents the applied pressure. The pressure exerted by a column of fluid of height h and density ρ is given by the hydrostatic pressure equation, P = hgρ. Therefore the pressure difference between the applied pressure Pa and the reference pressure Po in a U-tube manometer can be found by solving Pa − Po = hgρ. If the fluid being measured is significantly dense, hydrostatic corrections may have to be made for the height between the moving surface of the manometer working fluid and the location where the pressure measurement is desired.

Any fluid can be used, but mercury is preferred for its high density(13.534 g/cm³) and low vapour pressure. For low pressure differences well above the vapour pressure of water, water is a commonly-used liquid (and "inches of water" is a commonly-used pressure unit). Liquid column pressure gauges are independent of the type of gas being measured and have a highly linear calibration. They have poor dynamic response. When measuring vacuum, the working liquid may evaporate and contaminate the vacuum if its vapor pressure is too high. When measuring liquid pressure, a loop filled with gas or a light fluid must isolate the liquids to prevent them from mixing. Simple hydrostatic gauges can measure pressures ranging from a few Torr (a few 100 Pa) to a few atmospheres. (Approximately 1,000,000 Pa)

A single-limb liquid-column manometer has a larger reservoir instead of one side of the U-tube and has a scale beside the narrower column. The column may be inclined to further amplify the liquid movement. Based on the use and structure following type of manometers are used[2]

Simple Manometer

Micromanometer

Differential manometer

Inverted differential manometer

For more information about nanometer, you can go to http://en.wikipedia.org/wiki/Manometer

Hope I helped. :)