When you look at your dashboard what you are actually looking at is an instrument cluster. Within in the instrument cluster are several individual clusters, or gauges, that produce readings on certain aspects of the car. These readings are to inform you of different aspects of your car that are important for you to know. This information helps you to take care of your car and prevent further damage as well as know when to go to the gas station to fill up.
One of the gauges in the instrument cluster is the speedometer cluster. The purpose of the speedometer gauge is to tell you how fast your car is traveling down the road. The gauge is the most looked at gauge and can prevent you from getting a ticket or causing an accident from going too fast.
From time to time a speedometer cable may wear out. It may need to be replaced or simply greased. One way that you will know that there is likely a problem with your speedometer cable is you will hear a loud ticking sound in your car as you drive down the road. If you hear this sound, it is time to figure out if you need to replace the speedometer cable or if it just needs to be greased.
For those people that fancy themselves mechanically inclined, you can likely change or grease the speedometer cable yourself. This can save you a lot of money if you can do this yourself. You will find the speedometer cable located behind the instrument cluster. You should have some knowledge and resources at your disposal before you try to remove the instrument cluster or the speedometer gauge.
Removal of the speedometer cluster may be different from car to car, but it should be easy to remove on most cars. There are screws that need to be unscrewed before you can remove the speedometer cluster. The user's manual may give you some insight into which screws you need to take out in order to remove the speedometer gauge.
Once the screws are removed you can pull the speedometer out of the instrument cluster. Once you have removed the speedometer from the instrument cluster, you will be able to see all of the cables behind it. Make sure that you get the speedometer cable and not another one. If you pull the wrong cable you will find yourself upset, frustrated, and spending a lot more time than you planned on. If you aren't sure, consult a repair manual before proceeding at this step.
If you are nervous about messing things up on your car, you are probably better off taking it to the auto repair shop and having them do it. If you do not have any auto mechanic experience and do not enjoy puzzles, then attempting this repair is likely to cause more stress than the money saved to do it on your own.
If you decide to take the car to a shop, you can search the internet for repair shops that are near you. You can also use the internet to compare pricing between shops. Even though you will be paying more money than if you did it yourself, you can still save money by getting the best price from shops located near you.
If you are into watches with altimeters you need to know the basics of how they function. They're not all that complicated, but it is good to understand how they work so you can draw inference from the data they give you.
The altimeter readout on the timepiece is simply a translation of barometric pressure. The barometric pressure technology is what drives much of these watches' altitude and weather predicting capabilities. Thus, without a barometer, these watches would be just another watch. The small aneroid wafer barometer technology that is housed inside the watch case is really the brains of the entire device.
But, how does the watch read barometric pressure? I mean, the darned thing is so small - how can it possibly contain something as bulky as a barometer? What the devices were in the beginning there was no way that these things were going to be functional on such a small scale. However, with miniaturization of electronics, there are ways of sensing air pressure without having to actually have a column of mercury involved.
Well, there are 2 basic types of barometers - mercury and aneroid. Both measure outside air pressure and both measure that outside air pressure in terms of "inches of mercury".
Here are the 2 types described in a little more detail:
1. Mercury barometer - this is the original design and the one that really defined the science of weather prediction. The mercury serves as a translator of atmospheric pressure. That is, the pressure on the mercury by the air causes it to depress downward and make the level of the fluid rise in the tube.
2. Aneroid - this is the type of system that drives the altimeter in an airplane. It is very small and senses the air pressure and aneroid wafer meaning a wafer that has a vacuum inside. It is very sensitive to changes in pressure from the outside air. This is really what makes it possible to have watch altimeters in the first place. This is the only way you could get this type of information in the space so small.
Watches with altimeters couldn't function without barometers. The precision of the barometer in the timepiece will determine how much good you get out of the altimeter function on the watch. Without the miniaturization of electronics that preceded these watches with altimeters, you would have to keep each one of these devices separately maintained - and altimeter, a compos, a barometer, a title chart. All these things would have to be housed in separate devices.
While many weekend warriors head for the outdoors to escape the headaches of modern life. The outdoor experience can be enhanced without ruining the natural aspect of the trip with a serious weather instrument like a barometer.
With that in mind, there is a hand held barometer on the market has functional weather features and is light weight. Most barometer are too heavy to take with you when hiking in the outdoors, but with a hand held barometer that weighs only a couple of ounces you will definitely want to add it to your backpack when hiking. A hand held barometer is even great for taking on long trips when weather information might prove vital.
With a barometer that is hand held rather than when it is worn watch style on your wrist, there is always a danger of leaving it hanging some where. Even with the danger of accidentally leaving it hanging in a tree some where, many prefer a hand held barometer over those big and bulky barometers that you where on your wrist. Often times the watch style barometers have displays and buttons that are simply just too small. With a hand held barometers the documentation is clear, although the type is very small. It seems like a huge manual until you realize it comes in six languages, although it is not complex, navigating through the features is obvious.
If you only use these types of barometers occasionally, then you will probably need a refresher run through the manual before heading out for the outdoors. However, if you use it frequently, then you will have no problem remembering how to access the various features. These hand held barometers stores pressure information for twenty-four hours and shows a six hour trend on all screens. A pressure change alarm sounds when pressure drops twelve-tenths in inches of mercury or more in a three-hour period, which is a sign of impending bad weather.
The barometer memory keeps maximum and minimum pressure and temperature for the last twenty-four hours, and thirty minute reading for the last three hours, and three hours interval readings from three hours to twenty-four hours. The altimeter also has an alarm, and logs altitude whether it is a gain or a loss, cumulative gains and losses since the last log reset, maximum and minimum altitude, the average rate of ascent and descent, starting date, time of the log, and any altitude points you enter. The barometer and altimeter logs might seem minor, but they are the essence of a good weather instrument. It is the tracking of barometric temperature over time that allows weather forecasting.
One cool feature is a weather station and altitude feature. In weather station mode, the device assumes that altitude is locked like you are in a camp, so all pressure changes are due to weather. In altitude mode, it assumes pressure changes are due to elevation change in altitude as during an ascent. With all of these excellent weather features, you will be surprised to learn that the bottom of the temperature range is minus five degrees Fahrenheit, while the altimeter goes to twenty-nine thousand feet. This seems like an unreasonable limitation but in winter even at elevations of ten thousand feet temperatures drop well below five degrees below Fahrenheit.
Air is so light that you need the special instrument called a barometer to measure air pressure. The barometer was first thought of by an Italian scientist named Torricelli, in 1644. A simple experiment showed him that air had pressure, and that this pressure could be measured. You can do this same experiment. All you need is a glass tube about 3 feet long, closed at one end; some mercury (a metal sometimes called quicksilver); and a small dish. Fill the tube and the dish with mercury.
Hold your finger over the open end of the tube and quickly turn the tube upside down in the dish. You now have a mercury barometer. The mercury in the tube will drop until it is about 30 inches above the dish. Fifteen pounds of air pressure, which is normal, will usually hold up about 30 inches of mercury. If the air pressure is lower, the height of the column of mercury will be less than 30 inches. If the air pressure is greater than 15 pounds, the column of mercury will be higher than 30 inches. You can use a mercury barometer to help predict the weather. When the column of mercury begins to fall rapidly, it usually means that bad weather is ahead, because windy rainy weather usually follows a drop in air pressure.
After a storm is over, the mercury will climb back to 30 inches You may wonder why water cannot be used instead of mercury. The reason is that water is so much lighter than mercury that it would take more than a 34-foot tube of water to measure air pressure. Three hundred years ago, a German named von Guericke made a water barometer that was taller than his house. He had to cut a hole in the roof so that it would fit. In order to see the top of the water column, he put a little wooden doll in the tube. The doll floated on top of the water. When the pressure was high, the doll would bob up above the house top. When the pressure was low, it would disappear below the roof. Von Guericke's neighbors did not know what made the doll appear and disappear. They did not know it was air pressure. They thought that Von Guericke was a magician. When they threatened to kill him, he took down his barometer.