Hydrometer Definition in Science

A hydrometer or hydroscope is a device that measures the relative densities of two liquids. They are typically calibrated to measure the specific gravity of a liquid. In addition to specific gravity, other scales may be used, such as API gravity for petroleum, Plato scale for brewing, Baume scale for chemistry, and Brix scale for wineries and fruit juices. The invention of the instrument is credited to Hypatia of Alexandria in the latter part of the 4th century or early 5th century. Key Takeaways: Hydrometer Definition A hydrometer is an instrument used to measure liquid relative density based on buoyancy.Usually, a hydrometer consists of a sealed tube that is wider at the bottom than the top and contains a heavy ballast. When placed in a liquid, the hydrometer floats. Markings on the tubes stem correlate to the liquids relative density.The function of a hydrometer is based on Archimedes principle. An object suspended in a fluid experiences a buoyant force equal to the weight displaced by the submerged portion of the object. Hydrometer Composition and Use There are several different types of hydrometers, but the most common version is a closed glass tube with a weighted bulb at one end and a scale going up the side. Mercury used to be used to weight the bulb, but newer versions may use lead shot instead, which is much less hazardous in case the instrument breaks. A sample of liquid to be tested is poured into a sufficiently tall container. The hydrometer is lowered into the liquid until it floats and the point where the liquid touches the scale on the stem is noted. Hydrometers are calibrated for various uses, so they tend to be specific for the application (e.g., measuring fat content of milk or proof of alcoholic spirits). How a Hydrometer Works Hydrometers function based on Archimedes principle or the principle of flotation, which states a solid suspended in a fluid will be buoyed up by a force equal to that of the weight of the fluid that is displaced. So, a hydrometer sinks further into a liquid of low density than into one of high density. Examples of Uses Saltwater aquarium enthusiasts use hydrometers to monitor the salinity or salt content of their aquariums. While the glass instrument may be used, plastic devices are safer alternatives. The plastic hydrometer is filled with aquarium water, causing a tethered float to rise according to salinity. Specific gravity can be read on the scale. Saccharometer - A saccharometer is a type of hydrometer used to measure the concentration of sugar in a solution. This instrument is of particular use to brewers and winemakers. Urinometer - A urinometer is a medical hydrometer used to indicate patient hydration by measuring the specific gravity of urine. Alcoholmeter - Also known as a proof hydrometer or Tralles hydrometer, this device simply measures liquid density but isnt used to directly measure proof of alcohol, since dissolved sugars also affect the reading. In order estimate alcoholic content, measurements are taken both before and after fermentation. The calculation is made after subtracting the initial reading from the final reading. Antifreeze Tester - This simple device is used to determine the ratio of antifreeze to water used for engine cooling. The desired value depends on the season of use, hence the term winterizing when its important the coolant doesnt freeze. Sources Assaad, F.A.; LaMoreaux, P.E.; Hughes, T.H. (ed.) (2004). Field Methods for Geologists and Hydrogeologists. Springer Science Business Media. ISBN:3540408827.

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Dr. Jekyle And Mr. Hyde - Book Report Essay - 612 Words

1. Name of Book? The name of the Book is Dr. Jekyll and Mr. Hyde. 2. Author of Book? The author is Robert Louis Stevenson. 3. Setting? The setting took place in London England in the year (1885 and 1886). 4. Identify the theme of your Book. According to the author every person has good and bad inside of him. There is a continuous battle between the two forces, when the bad force won Dr. Jekyll committed suicide which is a lesson for us to keep the good force always on the outside and inside of us to live in harmony and peacefully. 5. Story. This book is about a man called Dr. Henry Jekyll he is a rich man who lived in the city of London in 1885. He was a strange character, who was conducting experiments on him self by taking drugs†¦show more content†¦They accepted the offer and went with him to a house where he brought out a Checkbook in the name of Dr. Jekyll and signed as Mr. Hyde. Mr. Enfield took Mr. Utterson and showed him the door to that house. A new clue is added to Mr. Uttersons knowledge. To follow the mystery Mr. Utterson started to get more suspicious because Dr. jekyll never mentioned Mr. Hydes name to him. He then went to visit Dr. Lanyon, a very close friend of Dr. Jekyll, to ask him about Mr. Hyde. Though Dr. Lanyon knew Dr. Jekyll but he had no idea about Edward Hyde. Thereafter Mr. Utterson kept watching the old black door night after night, finally at the third night he saw a little man wearing large clothes approaching the door. He stepped up to him and addressed him by the name of Mr. Hyde . The man answered back how do you know me. Mr. Utterson told him that Dr. Jekyll informed me about you because I am his lawyer. The man ignored Utterson and quickly unlocked the door, walked in and shut the door behind him. Furthermore Mr. Utterson went to Dr. Jekylls house and asked his servant, Poole, whether Dr. Jekyll is in the house or not. Poole said that he was out. Then he asked him if he knows a Mr. Hyde and the servant answered that he is a friend of Dr. Jekyll however he had never met him because he usually comes in through the back door of the laboratory. To sum up Mr. Uttersons search for the true identity of Mr. Hyde, he investigated with all the mutual

Human Resource Management Overview free essay sample

Human Resource Management is a very important key to any business there are many areas that relies on the people that work in this field. Working in this field takes a lot of dedication and time not only as a person but as a team member as well. Let me go ahead and get started discussing the importance of Human Resource Management. First of all, what is Human Resource Management also known as HRM? Human Resource Management is a group of people within an organization that focuses on recruiting new employees, providing directions to the current employees, etc.Human Resource Management responsibility is to work with issues related to people such as compensation, hiring, performance management, organization development, safety, wellness, benefits, employee motivation, communication, administration, and training [ (About. We will write a custom essay sample on Human Resource Management Overview or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page com) ]. Human Resource Management is also a strategic and comprehensive approach to managing people and the workplace culture and environment [ (About. com) ]. Effective Human Resource Management enables employees to contribute effectively and productively to the overall company direction and the accomplishment of the organizations goals and objectives [ (About. om) ]. The goal of Human Resource Management is to maximize the productivity of an organization while treating employees with respect and keep them safe at the same time. What is the primary function of Human Resource Management? When it comes to a primary function to Human Resource Management; this is a difficult area because there is more than one function that is important in this area. As I can recall there are four main functions that revolves around this job category. The first major function is what they call acquisition in which this consists of planning for employees which involves the following; needs of employees, skills needed, recruiting, and hiring (11Ju). The second major function is development which consists of basically training activities (11Ju). The third function involves compensation which includes paying the employees and giving them incentives (11Ju). The fourth function that I can think of is maintenance which involves employee benefits, insurance, and etc (11Ju).So with this being said I can not narrow it down to one primary function. The main role for Human Resource Management in an organization’s strategic plan is the following. Human Resource Management works directly with the employees and they are aware of the employees needs and aware of the surrounding that the employees are put into. So therefore their main role is to help the others decide if a certain change would benefit or hurt the employees’ production, etc.Having some members from Human Resource Management aware of the strategic plan is critical when an organization is making plans to change something because they are able to say what they need to in order to keep the employees safe in the environment while making changes as necessary. If the HRM is left out of this type of planning there could be problems in a lot of different areas, Human Resource Management is able to see if the actions will interfere with the employees progress.In conclusion to this paper, there have been several important areas covered concerning Human Resource Management throughout this paper. The first section consisted of material that described what human resource management is in detail. The next section that was covered is concerning what the primary function of Human Resource Management is. The last section that was cove red is the role that human resource management plays in an organizations strategic plan.