MEASURING TAPES
Measuring tapes are made in a variety of lengths. materials. and weights. They are also
graduated in several ways. Graduation marks and numbers are either etched, stamped. or printed
on tape. The following are some of the most commonly used types of measuring tapes:
1. Steel Tape. A steel tape also known as surveyor's or engineer’s tape. is made of a ribbon of steel
0.5 to l.0 cm in width. and weighs 0.8 to 1.5 kg per 30 meters. Lengths of 10. 20, 30, 50 and 100
meters are available. The 30-m tape is most common. Usually steel tapes are wound on a reel. or
done up in loops about 2 meters long to make a figure 8. Steel tapes are designed for most
conventional measurements in surveying and engineering work.
2. Metallic Tape. Metallic tapes are sometimes called woven tapes. They are made of waterproof
linen fabric into which are woven longitudinally small brass. copper, or bronze wires to increase
its strengths and reduce stretching. Metallic tapes are usually 30 or 50 meters long, 10 to 15 mm
width, and come in enclosed reels. It is used principally for measuring short distances in locating
details for maps. earthwork cross sectioning. and for other measurements where a light a flexible
tape is desirable. This type of tape is unsuitable for precise measurements and should not be used
around electrical installations.
3. Non-Metallic Tape. Is a type of tape woven from selected synthetic materials with strong
dimensional stability. The tape is in turn coated with a plastic material to reduce the effects of
moisture. humidity. and abrasion. Non-metallic tapes are safe to use the working around electrical
installations or for any type of work where a metallic tape would be unsuitable.
4. lnvar Tape. A special tape made of an alloy of nickel (35%) and steel (65%) with very low
coefficients of thermal expansion (1/30 to l/6O that of a steel tape). its name was derived from the
word “invariable" since it is less affected by temperature changes than in a steel tape. lnvar tapes
are used only for precise measurements in geodetic work and for checking the length of other kinds
of tape. They are about ten times as expensive as ordinary steel tapes. The use of invar tapes will
require very careful handling since the alloy is soft and somewhat unstable. It is a kind if tape which
gets easily bent and damaged.
5. Lovar Tape. A newer type of measuring tape which has properties and costs somewhere between
those of conventional steel tapes and the invar tape.
6. Fiberglass Tape. This tape is made by weaving fiber-glass in a longitudinal and transverse pattern.
They are strong and flexible and will not shrink or stretch appreciably with changes in temperature
and humidity. A fiber glass tape is best suited for use in the vicinity of electrical equipment.
7. Wires. Before thin flat steel tapes were produced. wires were utilized in measuring lengths. They
are still practical to use in special cases as in hydrographic surveys.
8. Builder’s Tape. Are tapes having smaller cross sections and are lighter in weight than the
engineer’s tape. Such are graduated to suit commonly used dimensions in building construction.
9. Phosphorus-Bronze Tape. A rust-proof tape designed for used in the vicinity of salt water.
10. Nylon-Coated Steel Tape. Is a flexible crack-resistant steel core tape with a coating of
permanently bonded non-conducting nylon. It is designed to be resistant to corrosion and is
immune to rust.
TAPING ACCESSORIES
1. Range Pole. Range poles which are also known as flags or lining rods. are used as temporary
signals to indicate the location of points or the direction of lines. and to mark alignment.
2. Tape Clamping Handles. With its scissor-type handle, tape clamps are used to apply tension with
quick clamps of any part of a steel tape without causing damage to the tape or hands of the
tapeman.
3. Chaining Pins. Chaining pins are sometimes called surveyor’s arrows or taping pins. They are
stuck in the ground to mark the ends of measured tape lengths. or partial tape lengths and may
also be used in place of wooden hubs or stakes.
4. Tension Handle. This device, which is also referred to as a sprig scale. is used at one end of a
tape for insuring the application of the correct amount of pull on the tape during measurement.
Tension handles are only used in precision taping. They are usually dispensed with in measuring
distances requiring ordinary precision.
5. Tape Thermometer. in precision taping. thermometers are used to determine the temperature
of the air and the approximate temperature of the tape during measurement.
6. Plumb Bob. In taping, plumb bob are used for projecting the tape ends to the ground when the
tape must be suspended above the measured line.
7. Wooden Stake or Hub. Stakes or hubs are made of 5 cm x 5 cm by 30 cm wood to mark points.
corners. or stations on the ground. These temporary markers are required in stalking out a building
or structure, running the centerline of a building or structure. running the centerline of a proposed
road. and in stalking out any line or grade.
8. Leather Thongs. A leather thong ls attached to a ring located near the zero-meter mark of the
tape to provide a comfortable grip on the tape when measuring.
9. Hand Level and Clinometer. The hand level and clinometer is usually a 15m long device which
consists of a metal sighting tube with a level of bubble. At one end, the tube has a peep sight
opening for viewing a sighted object.
10. Tape Repair Kit. A tape repair kit should be taken along when an extensive taping operation is
to be performed at remote areas. These kits will allow emergency repairs to be made on damaged
or broken tapes.
ll. Crayons. Marking crayons used in surveying are usually lumber crayons. They are about 10 cm
along and are hexagonal in cross section.
COMPOSITION 0F TAPING PARTY
1. Head Tapeman - the person responsible for the accuracy and speed of all linear measurements
with the tape. He determines and directs the marking of points or stations. orders the clearing out
of obstructions along the lines to be measured, and is the person who carries the zero end of the
tape ahead.
2. Recorder - keeps a record of all measurements. sketches. and observations taken during the
process of measurement. He also checks by pacing all measurements made by the tapemen for
possible errors. mistakes. and blunders.
3. Flagman - the person whose duty is to hold the range pole (or flagpole) at selected points. He
also helps the tapemen in making measurements and assists in clearing out obstructions along the
line to be measured.
4. Rear Tapemen - the person whose duty is to assist the head tapeman during a taping operation.
He is the one who holds the 30-m end or any intermediate meter mark of the tape during a
measurement.
THE PROEDURE OF TAPING
l. Aligning the Tape. When a line is to be measured. both ends must first be marked. It may also be
necessary to establish a few intermediate points to serve as guides in obtaining a straight line. Range
poles, held at both ends of the line are used as markers and chaining pins are stuck to the ground
to mark the intermediate points. The head tapeman hands over one chaining pin to the rear
tapeman. he then takes the zero end of the tape and moves forward in the general direction of the
line to be measured. At the initial point. the rear tapeman carefully unrolls the tape from its reel
and sees to it that the tape is not looped or unduly twisted so as to cause kinks on the tape.
When the 30-m of the tape comes up even with the initial point, the rear tapeman calls
out “stop”. At this command. the head tapeman halts and positions himself along the line to be
measured by vocal or hand signals from the rear tapeman.
2. Stretching the Tape. With the 30-m mark held at the initial point. and the head tapeman aligned.
the rear tapeman calls out “all right” or “OK". The head tapeman takes his position just to the left
(or right) of the line. kneels. and pulls the tape taut. The tape may be held between the fingers and
the palm. He then sticks a chaining pin into the ground to mark the zero-meter end of the tape.
When the head tapeman sets his pin. the rear tapeman should be holding his end of the tape
precisely on the mark. A steady and firm pull. generally between 4 and 7 kg. is applied on one end
of the tape during stretching. No measurement should be made without stretching the tape since
tapes are correct in length only when a standard pull is applied to it. If the tape is stretched less
than the required standard pull. all recorded measurements will turn out to be "too short". The
tape will correspondingly be “too long" if the pull applied is greater than the standard pull. To
maintain a steady pull. the leather thongs at the tape’s end should be wrapped comfortably around
one hand. A firm pull, could also be made by holding on to a chaining pin slipped through the eye
at the end of the tape, or by using a tape clamp. An efficient method of communication must
continue to be established between the tapeman to obtain accurate results, save time. And avoid
jerking the tape.
3. Plumbing. When the ground is covered by obstacles. weeds. iow brush. And irregularities in the
ground surface, it will be difficult or impossible to lay the tape. On the ground during measurement.
Both ends of the tape should instead be held above ground (about the level of the waist or chest)
and in a horizontal position. Also. Each end of tape is marked by positioning a plumb line (defined
by a plumb bob and string) held by both tapemen. When the point is being plumbed over soft
ground. The plumb bob is dropped and a pin is carefully set in the hole made by the plumb bob
point. if the length to be measured is less than a full tape .length. the head tapeman moves the
plumb line to a selected point on the tape where it can be stretched horizontally. or over a specified
or required ground mark.
When the tape is aligned, stretched. and. ready for marking. the rear tapeman continues to
hold a plumb line over the fixed point while the head tapeman plumbs his end of the line and
marks it on the ground. A firm stance is important. The head tapeman should position the plane
of his body parallel to the tape, with his legs well spread apart. His forearm should be in line with
the tape. and he should snug it comfortably against his body.
During the measurement. it is important to determine if the tape is held nearly horizontal.
A hand level should be used to check if the tape ends are held correctly at the same elevation so
as to obtain an accurate measurement. lf hand level is not available, the tape may be estimated to
be horizontal by eye. 'The task of determining if the tape is held horizontal during measurement
may be assigned to the recorder.
4. Harking Full Tape Lengths. When a full tape length measured the rear tapeman holds his end of
the tape opposite the pin earlier set on the ground. The head tapeman after being lined-in properly.
exerts the required pull on the tape. notes the zero end and sets a pin beside it. The chaining pin
may be set vertically in the ground or given a slant at right angles to the line measured. if the head
tapeman is satisfied that the measurement was done accordingly. he signals that the point marked
is acceptable. The rear tapeman then picks up the rear pin set on the ground and both tapeman
move forward. The tape is dragged by the head tapeman who comes to a stop after pacing an
equivalent tape length. This procedure is repeated until a partial tape length is to be measured at
the end of the line.
In some instances. taping would be done on a hard surface such as a concrete or asphalt
road. or on steel rails along a railroad. Since pins could not be used. the end of the tape is marked
by using colored crayons (keels). chalk. or paint. The number of tape lengths is recorded beside the
mark to keep count or the number of full tape lengths measured.
5. Tallying Taped Measurements. At the initial point the rear tapeman holds one pin and the head
tapeman begins with ten pins carried on his steel ring. This is the reason why a set of eleven pins is
normally used during taping operations: The first pin which the rear tapeman holds indicates 'that
one tape length has already been measured, and the total number of pins in his possession (not
counting the pin still set in the ground) indicates the total number of full tape lengths that have so
far been measured.
When the head tapeman sets his last (lith) pin. a tally is made, The rear tapeman who by
then accumulates ten pins. brings these forward and hands it over to the head tapeman. The same
taping process is then continued. Thus, the number of tallies indicates the number of tape lengths
which have been measured. if a 30-m tape is used, each tally of 10 pins means that 300 meters has
so far been measured.
6. Measuring Fractional Lengths. When the last segment of the line is to be measured this will often
be a measurement which will consist of a fractional tape length. Upon reaching the end of the line.
the head tapeman comes to a halt and the rear tapeman positions himself at the last pin set. The
rear tapeman holds the tape in such a manner that a whole meter mark is aligned with and opposite
the pin. The terminal point should fall within the end meter-mark of the tape which is subdivided
into smaller graduations. usually in centimeters. After the correct pull is applied. the head tapeman
observes the number of centimeters which extends beyond the terminal point of the line measured
while the rear tapeman observes the number of the meter mark he is holding at his end of the tape.
The number of centimeters which the head tapeman observes is subtracted from the meter reading
which the rear tapeman observes to obtain the measured fractional length. Since it is at this part of
the measurement that mistakes in taping frequently occur. tapemen should exercise extreme care
during this particular measurement.