Estimating Tools Required for Installation

Tools Required for Estimating

Tools Required for Estimating

Estimating Tools Required for Installation- Different types of tools are used to estimate any electrical project, which are known as estimating tools. In other words, all such tools or instruments, which are used for the installation of any electrical project, are called estimating tools. The list of these tools is as follows;

(1). Map Measure

(2). Tap Measure

(3). The Tally

(4). Architect’s Scale

(5). C-Clamps

(6). Pencils & Crayons

(7). Cleaning Plans Liquids

(8). Slide Rule

(9). Drawing Board & Instruments 

(10). Misc. Tools & supplies

The detail of the aforementioned tools is as follows;

Map Measure

A map measure is used in order to measure any large construction work or a large electrical project. A map measure is also known as a roto meter amongst professionals. Its significance has expanded tremendously due to its continuous application over the years. Through a map measure, an accurate measurement of feeders as well as branch circuits can be carried out pretty quickly. It also proves to be a very handy tool to measure or check the dimensions of any building. 

As different types of map measure or roto meters are available in the market, therefore a lot of caution should be exercised while purchasing them. After making a comparison of different types, always a top-quality and particularly such a roto meter should be purchased, which instead of being used for multiple assignments, can be suitable for the measurement of some specific type of a task (i.e., every type of roto meter can only accurately measure some specific type of any work, therefore the type of roto meter which can be used for accurately measuring any job, should be kept in mind). Practically, all roto meters are foreign-made, and most often, the manufacturers’ name is not written on them. That’s why its selection tends to be somewhat difficult. Remember that the best method of making a correct selection is that such a roto meter be selected with the specifications which are nearest to your measurement requirements. 

A pocket watch size and type, map measure, or roto meter is generally used for electrical estimating. Its diameter turns out to be 1 ¾ inch and its thickness is about 9/16 inches. There is a reset pin on its top while a small wheel or a contact wheel on its bottom part. Three dials are mounted on the front part of this roto meter, of which, one of the dials is large whereas the remaining two dials are smaller in size. The large dial is marked with inches whereas small dials are marked in feet. On one of the smaller dials, there are markings in feet from 0 to 10 feet, whereas on the other small dial, 0 to 100 feet marks are normally inscribed. 

In order to get measurement, the contact wheel fitted on the roto meter is run along the line, the measurement of which has to be done. There are some small gears fitted along with this wheel, which prevent the wheel from slipping during its run. Whereas the wheel resetting button is not too long, rather it is pin–type (technically, it is known as the stem). This small pin-type stem prevents accidental resetting of the wheel. As the contact wheel is run along a measurement line, the reading on its dial increases. However, adopting a habit of taking a reading from the largest scale (i.e., dial having 0 to 100 feet) turns out to be far better. During taking a reading, the instrument is kept straight upright, so that the contact wheel may visibly touch the measurement line. Moreover, the instrument should be held in their hands in such a way, that they do not accidentally touch the measurement reset pin. A great advantage of a roto meter is that during a large measurement, one hand of the estimator remains free for marking purposes. Moreover, if a person taking a measurement stops momentarily to take some notes or write down anything else, in such a way there is no need to record the measurement which has been taken. Because the entire measurement record is available on the meter. When notes are completed, further measures can be commenced. 

Tap Measure

The tape measure is a type of steel tape, through which measurement is carried out directly into feet, and on which a specific mark has been inscribed for every foot while taking measurement or reading. Some estimators prefer tape measure over map measure. A 3/16-inch size tape measure or steel tape is commonly available in the market, on which marking in feet is inscribed directly to take measurement. Tape measures are available in ¼ inch and 1/8-inch scales. On ¼ inch scale tape, there are marks up to 48 ft. of 12 inches, whereas in 24 inches, there are marks up to 96 ft. Similarly, on a 1/8 – inch scale tape, there are marks up to 96 ft. in 12- inches, and 192 ft. in 24- inches. Remember that on a ¼ inch scale tape, the rest of the markings are done on intervals of ¼ inches, whereas the markings on a 1/8 – inch scale are done on intervals of 1/8- inches. 

Tap measure is used both for small as well as large measurements. To take a measurement, hold the steel tape between your right hand’s thumb and index finger, and push out the tape with your left hand. All measurement marking is always carried out through the right hand. As soon as a measurement completes, take your right hand to the next starting point for the next measurement. And, pull out the tape till the end of the line which has to be measured, and note down the reading. As such, measurement of any project can be performed. Moreover, an allowance for shrinking is added to the total of all resulting measurements. Getting measurement through a steel tape is relatively easier as compared to a roto meter, however, the possibility of accidental measurement errors cannot be ruled out altogether. 


Tally is a type of instrument which is used by an estimator for recording counts (i.e., storing counts) so that whenever he feels necessary during the counting, he stops taking notes or studying details. 

It is a difficult task to memorize counts of several measurements in a large project, which requires substantial studies, whereas the application of tally has made this task comparatively easy. As the estimating operation progresses, the tally instrument records or stores all data of the previous counting, thus tally provides an opportunity to collect scattered notes and nearly ambiguous details of any project. Actually, an estimator counts measurement and keeps it in his mind in the beginning, and tally or compares the tally count recorded with the calculation he has performed in his mind. As such, an inspection of an entire electrical project accomplishes as a result of an automatic tally operation (i.e., recording counts). The body diameter of a tally instrument tends to be approx. 1 ¾ inch whereas its thickness tends to be 1 1/8 inches. A ring is normally fitted along with the body of the tally instrument, which clasps the left index finger. This instrument can be operated for counting quite easily with the help of the left thumb (just similar to a stopwatch). The reset knob (reset stem) which is set opposite to the hand palm, normally remains independent of the reset gear through a rigid spring. In order to reset the instrument, the reset knob is pushed inwards and rotated. After this operation, as a reset knob is released, the spring also lets loose the knob. The purpose of such an arrangement is to avoid an accidental resetting of the instrument. Because, if the instrument resets by accident, all previously stored record is feared to be lost. 

Architect’s Scales

For designing the layouts of huge projects on a sheet, an appropriate scale has to be devised. If a scale is not ascertained, it becomes difficult or virtually impossible to depict any gigantic drawing on a sheet. For example, representing a 1-meter length on some drawing sheet as 1 cm is known as fixing of scale. Through a selection of such different appropriate scales, an electrical estimator designs a layout of any project on a drawing sheet. For this purpose, cards with different scales are being used, which are known as architect scales. 

Three to four scales are used in any project. In a single sheet, on which two or more two parts of any building exist, in such a situation there may be separate scaling for every part. However, confusion may also be experienced occasionally in the working due to the application of multiple scales, as a result of which estimating task also becomes difficult. Before estimating the quantities of materials being used, an estimator must carefully check every part of the project, and ensure that every drawing has been represented through an appropriate scale (i.e., no drawing should be undertaken without scales). Particularly, wherever more than two drawings are found on a single sheet, in such a situation scale of every drawing should always be written above that drawing. 

C – Clamps

In large electrical plans, these clamps are used to hold sets of large sheets on an estimated table. For this objective, normally 3-inch C–Clamps are used. so that whenever sheets are bent, they do not drop down from the table. Thus, plans occupy the minimum possible space, and while turning up or down, sheets do not fall from the table due to their weight. Most often, sheets are turned back and forth for reference purposes (i.e., for reference of different sets). Sheets can be moved back and forth quite conveniently on the table with the assistance of c-clamps, instead of opening a folded sheet for reference purposes every time. In other words, if every sheet is folded after having been completed, and whenever, a reference of any particular sheet is required, it is searched, opened, and folded once again. In this way, a considerable stint of time is wasted. Moreover, the opening and folding of large sheets also require considerable space. Through the application of c-clamps, all these hardships are turned into comforts, and very little time is consumed on searching any particular sheet. 

Pencils and Crayons

The application of colored pencils and crayons is compulsory for checking purposes. Different types of colored pencils are commonly available in the market. Some of these pencils are not suitable for estimating purposes, because their markings are so hard, that they cannot be erased from a plan easily. Thus, such pencils should be used on plan sheets, which can make a mark through a little push, and these markings can easily be removed through ab eraser or any cleaning fluid. 

An estimator should make it a habit, always to use orange color for lighting, red color for power, and yellow color for signals. These color schemes can also be used for writing notes on any plan, underlining notes on plans, and for encircling ambiguous or obscure things. 

Multi-colored crayons can also be used to highlight conduit ways and for checking other types of materials on a blackboard. One of the advantages of using chalk is that its marking can easily be wiped out from any plan. Remember that crayons should be kept dry as far as possible. During the intense summer heat, a person who uses crayons should exercise caution, that his sweat neither touches chalk edges nor drops on a plan. 

Cleaning Plans Liquids

A need to clean a plan is always felt. For this purpose, cleaning liquids are used. Chalk marking on any plan can pretty easily be wiped out or cleaned through a dry cloth, however, if colored pencil markings are found on any plan, they can very easily be cleaned through a cloth having been immersed in Benzine, Naphtha, or Carbon Tetra Chloride.   

Slide Rule

A slide rule is generally used for drawing various markings or lines at the time of making any plan, which is generally made from steel or plastic. There are inch marks on one side of this rule, while on the other side, there are centimeters as well as mm markings. 

Drawing Board & Instruments

Drawing boards & corresponding instruments are also generally used as estimating tools for making plans and drawing different shapes. Through the application of these tools, plans and diagrams can be prepared with an accurate measurement vibrantly and attractively. They include different sizes of drawing boards, sheets, cards, corners, pins, stencils, etc.  

Misc. Tools & Supplies

Sometimes certain tools are required at the time devising different plans, which are not included in the drawing instruments. For example, paperweight, marker, paper cutter, string, staples, etc. These items come under the purview of different tools and supplies. In figure 9.2, different types of estimating tools and supplies have been illustrated. 

Next Topic: Estimating Forms Required for Installation

Previous Topic: Electrical Installation Estimating and its Importance

For electronics and programming-related projects visit my YouTube channel.

My YouTube channel Link

Engr Fahad

My name is Shahzada Fahad and I am an Electrical Engineer. I have been doing Job in UAE as a site engineer in an Electrical Construction Company. Currently, I am running my own YouTube channel "Electronic Clinic", and managing this Website. My Hobbies are * Watching Movies * Music * Martial Arts * Photography * Travelling * Make Sketches and so on...

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button