A rheostat is a device which is used to vary the resistance in an electrical circuit without interrupting the circuit.heostats are a kind of potentiometer. These devices can be used in a variety of settings, and are usually designed to be sealed so that environmental factors cannot interfere with the function of the circuit.
This chemical can cause allergic rhinitis and its symptoms, including a runny nose, sneezing, and itchy eyes. In addition to tree pollen, other common allergens include: grass pollen
People with allergic rhinitis generally experience symptoms after breathing in an allergy-causing substance such as pollen or dust. In the fall, a common allergen is ragweed. In the spring, the most common triggers are grasses and pollen.llergic rhinitis, like skin rashes and other allergies, develops when the bodyâs immune system becomes sensitized and overreacts to something in the environment that typically causes no problem in most people. Allergic rhinitis is commonly known as hay fever.