1 In the mercury barometer, atmospheric pressure balances a column of mercury, the height of which can be precisely measured. 2  Of the many different varieties of mercury barometers, most variations arise from different techniques for measuring the height of the mercury column.
Recognizing the Symptoms of an HIV Rash. 1  1. Check for a rash that is red, slightly raised, and very itchy. 2  2. Note if the rash appears on your shoulders, chest, face, upper body, and hands. 3  3. Pay attention to other symptoms that may occur when you have HIV rash.  4. Be aware of the causes of HIV rash.
HIV rash. Many people who have HIV experience skin rash or other skin symptoms at some stage of the disease. It can be the first symptom people with a new HIV infection have when the disease becomes more advanced. This rash can be very distressing for patients because it can be quite noticeable and cause embarrassment. We're here to help.