There are many different types of dynamometers available in the market and are widely used in the automobile industry. They are used for testing applications which measure torques by attaching restraining elements to the output shaft. This element then rotates with the shaft, allowing the dynamometer to determine the force needed to allow rotation. The force multiplied by the length of the lever arm then give the torque value. Engine dynamometers measure crankshaft torque, while chassis dynamometers provide information in regards to mileage and fuel economy.
Smaller dynamometers which are typically hand help are more traditionally used to measure tension and pulling forces, which drag down from pull hooks attached to the dynamometer. The hand held dynamometers tend to use hydraulic and spring loaded mechanisms that read functional capacities in the same form that small scales would. Like scales they measure in the form of weight, in Kg (which is internationally recognized) or Lb which is used throughout North America and Europe. Most of these devices are know as force gauges or hanging scales.
The measurement of force through the use of dynamometers allow many industries to progress through research and development in many areas such as telecommunications, technology, and electronics. Mechanical indicators which look like clocks and work mechanically are used for service field testing especially for power lines for telephone and electricity. The dynamometer can also be used for testing ropes for rescue systems for engine belts and bicycle spokes. In the technology industry, software developed for accelerometer - equipped smartphones allow for measurement of acceleration, gravity and horse power.
TYPES OF DYNAMOMETERS - MECHANICAL VS DIGITAL DYNAMOMETERS
Since the release of digital dynamometers the advantages of force measurement have become more wildly accessible as well as providing accurate results that can be quickly obtained. The output readings have a very exact value that can easily be connected via RS 232 cable to a printer in order to obtain recorded results that can be stored. The operating of the instrument is much more user friendly and the result can be obtained by the press of a button. Even newer advances have introduced completely wireless dynamometers such as the Industry Leader, the Dillon ED- Extreme which even allows the operator to connect various dynamometers to one single hand held remote controller, allowing complete freedom and endless possibilities to the operator.
Mechanical dynamometers have pointers to numbers on the dial face (which can come in different sizes such as 5” and 10” diameter dials). The operator must determine where the pointers position is and then record it. Therefore in the case where data is collected in the example of research purpose it would be preferable and more reliable to use digital dynamometer for which the data collected can be stored.
In terms of pricing the mechanical dynamometers are significantly more economical, however the digital have much more function options which include tare and data output, many of which are standard functions. The digital dynamometers are also manufactured to withhold more capacity, they can measure up to a whopping 100 tons.
Although in regards to the durability it must be stated that mechanical dynamometers are extremely heavy duty and can be very durable.
A common serious problem among dial dynamometer users is the failure to notice when the pointer makes a full revolution or two. Parts that are grossly out of tolerance may appear to be within tolerance to an inattentive operator. In contrast, digital dynamometers never come “back to zero,” eliminating this problem entirely. In fact, with the ability to display the actual part size, the concept of going back to “zero” or reading deviations is fading. Plus, all digital dynamometers can be made to signal out-of-tolerance dimensions, so a user is rarely required to make decisions.
As a new generation of engineers and machinery operators arises, the preference towards digital dynamometers increase and the demand for mechanical dynamometers fades out. This is because the advantages and benefits for the digital dynamometers grow allowing more industries to make use of them. The more concerning problem is that there are less and less technicians available to provide the maintenance and repair for the existing mechanical dynamometers available. Therefore many companies may opt out of using mechanical dynamometers because if damaged it may not be reparable or could be very expensive to repair.
Ref : http://www.mmsonline.com/columns/dial-vs-digital-indicators