The American Industrial Hygiene Association (AIHA) in their manual, Direct-Reading Colorimetric Indicator Manual (Second Edition, 1993) makes the following statement on detector tube accuracy: The accuracy of detector tubes generally is considered to be +/-25% of the reading.
How do Draeger tubes work?
Draeger tubes contain a chemical color reagent that transforms colorless chemical compounds into colored, and produce consistent results of absorption depending upon the concentration of the compounds they are subjected to.
What are detector tubes used for?
A detector tube is a graduated glass tube filled with a chemical reagent that will produce a color change, when exposed to the gas in question. It is used with a hand pump that will draw a sample into the tube. The tubes are generally supplied in packages of ten, and are sealed at both ends.
How do you use a gas detection tube?
How to Use Gas Detector Tubes
- Prepare the tube: Use the included tip breaker on the pump to remove both ends from the gas detector tube.
- Insert the tube: Push the pump handle all the way in.
- Align the pump: Turn the handle until the red guide mark on the top of the pump and the black mark on the handle align.
Are colorimetric indicator tubes accurate and precise?
The American Industrial Hygiene association (AIHA) in their manual, Direct-Reading Colorimetric Indicator Manual (Second Edition, 1993) makes the following statement on detector tube accuracy: The accuracy of detector tubes generally is considered to be +/-25% of the reading.
What is colorimetric titration?
Titration is a kind of volumetric measurement, whereby you measure the unknown indirectly by adding another chemical or reagent that will react with it to make a visible change. This approach is called colorimetric titration because you measure your progress through the use of a change in color.
What is a Drager tube?
Draeger Tubes are colorimetric gas detection tubes that are used to identify and detect different toxic and harmful gases. Every Draeger Tube is a glass vial that is filled with a chemical reagent, that will react with a specific chemical or type of chemical family.
How accurate are Draeger tubes?
Compared against less stringent accuracy criteria of +/- 35 percent, all Photovac GC results were acceptable but about 40 percent of Drager CMS results were not.
What is a stain tube?
RAE Systems colorimetric gas detection stain tubes, which are similar to Draeger tubes, enable quick measurement of a wide range of toxic and combustible gases and vapors. RAE gas detection tubes are easy to read, and provide a sharp, clear color change directly corresponding to the concentration of gas present.
Why do detector tubes have different ranges?
What range do the detector tubes measure at? For many gases and vapours, there are several concentration ranges available (ppm, %, Mg/m3, mg/l) giving you the flexibility to measure both low and high concentrations without sacrificing precision.
How do you read a detector tube?
To read the results, look at the measurements lining the tube and find the spot where the color ends. This color change, or stain as it is referred to, will have a length directly tied to the gas concentration. This can then be read directly on the tube, using the pre-printed gradations.
How will you proceed for colorimetric analysis?
For industrial applications, colorimetric analysis is performed by adding a coloring agent to the solution or metal to be inspected. Ideally, in such tests the applied chemical indicates the intensity of the color by initiating a reaction.
What are colorimetric detector tubes?
Colorimetric detector tubes are graduated glass tubes filled with chemical reagents that produce a color change when exposed to the gas in question. They’re used with hand pumps that draw a sample of air into the tube.
What is a colorimeter and how does it work?
A colorimeter takes three wideband readings along the visible spectrum to obtain a rough estimate of a colour sample. Traditionally, the word ‘colorimeter’ is used for a device, having three filters, that simulates human vision. Colorimeters can be classified into two types:
How does a Burnham colorimeter work?
The Burnham colorimeter (Burnham, 1952) is relatively simple in construction and utilises additive mixing of primary stimuli, made up of coloured filters and a light source. A transparent disc (Fig. 6.3) is divided into three sectors bearing coloured filters, red (R), green (G) or blue (B).
How accurate are commercial tristimulus colorimeters?
Most commercial tristimulus colorimeters are satisfactorily precise, but their measurements may not agree with the tristimulus values obtained by spectrophotometry. The oldest and simplest colour comparator is the Nessler tube, which was developed into the Duboscq colorimeter.
