| Model |
BM-III |
| Production |
Skid Resistance Tester |
| Checker |
003 |
| |
ISO9001 Certified |
I.Application
The apparatus is used to measure antiskid performance of high grade
roads and airport pavement both in lab and in-situ. It is convenient in
operation, and with precise testing results, stable performance.
II.Structure
1. Foundation: composed by T type legs, levelling screws, and bubbles.
2. Upright column: composed by one column, one lifting unit, one guiding rod
and one handle.
3. Releasing switch: fixed on the cantilever, used to remain level of pendulum
rod and release pendulum.
4. Steering system: including one tightening handle, one pendulum shaft, one
knuckle and one bearing, the whole system connects the pendulum,
secures its position and ensure free oscillation in the plane.
5. Scaling system: Including needle felt gasket, clamping cap, needle adjusting
screw and dial gauge. BPN is read directly from what the needle points.
6.
Pendulum: composed of upper and lower connectors, oscillation rod,
spring, lever, lifting handle, hammer shell, slipping chunk and rubber
chunk(76x25.4x6.35mm).
III.Technical parameters
a) Pendulum weight: 1500g
b) Distance of centre of pendulum gravity 410mm
c) Forward Static Pressure From Rubber Sheet To Pavement:2263g
d) Oscillation during free falling of the pendulum from slope 5o is no less
than 70 times.
e) Distance between oscillation center to outer edge of rubber sheet:
510mm
f)
Package Size:40x75x75cm,weight:17kg
IV.Operation
a) Points selection: select
five
representative
points from left side of
traffic direction on testing pavement, distance of every points shall be
5~10mm.
b) Levelling: Place the apparatus on the testing point and let the
pendulum oscillates to the traffic direction, turn the levelling screw and
center the levelling bubble.
c) Zero setting:
(1) Caliberation of pointer position: let the pendulum move to right side,
location clasp enters into releasing switch groove, turn the pointer to
right and make it paralled to the oscillation rod. Make long edge of the
ponter indicator be next to cantalever, another end of the indicator is
positioned on oscillation rod, and the pointer tip shall be next to convex
edge of the indicator, if not, adjust the screws accordingly. What the
pointer points is center of the oscillation rod.
(2) Relax the fixation handle and turn the lifting handle to lift the rod, thus it
could oscillate freely, tighten the fixation handle.
(3) Let the pendulum move to right side, push releasing button to make the
location clasp enter into releasing switch groove, and the oscillation rod
is on levelling releasing position. At the same time, turn the pointer to
make it be paralleled to the oscillation axial.
(4) Push releasing button, the pendulum move to left side and bring the
pointer move up and down. When the pendulum moves to the highest
place, receive it by left hand, the pointer shall points zero, if not, tighten
or relax adjusting screw to make the pointer point to zero.
d) Sliding length caliberation
(1) Clear the testing pavement by rubber brush
(2) Suspend the pendulum freely, center of the ruler aim to the oscillation
rod, sliding ruler be paralleled to testing direction and close to rubber sheet.
(3) Relax the fixation handle, turn the lifting handle and let it fall slowly, and
raise the lifting handle by right hand to make the pendulum move to right
side. Put a sliding lump on right side of the ruler, make it touch
pavement and align to ruler line; then raise the lifting handle to make the
pendulum move to left side. Put a sliding lump on left side of the ruler,
make it touch pavement and align to ruler line. Tighten the fixation
handle and double check sliding length. Fine tuning sliding length by the
levelling screw, make it to 126±0.5mm, ensure that the bubble shall be
in the center during fine tuning.
e) Measurement: watering pavement and clear slurry by rubber brush,
then watering again. Push release button, the pendulum slides from the
pavement, the pointer will point to the oscillation value( normally the
first value is not recorded). When the pendulum move back to right,
receive the oscillation rod by left hand, raise the lifting handle by right
hand to lift the sliding lump, and let the pendulum move to right side,
switch on, the fixation clasp enters into releasing switch groom, repeat
the steps and record results for 5 points(watering for every tests).
f)Result
(1) Test 5 times for one point and take the average. Take average of 5
points as oscillation value of pavement.
(2) Friction coefficient is the value of oscillation value devided by 100.
g) Attention
(1) Friction coefficient is influenced by season and temperature, therefore
date and temperature shall be recorded together with test results.
(2) Pavement structure, appearance and validity shall be described as well.
(3) When pendulum move back from left side, you have to receive the
oscillation rod by hand to prevent the sliding lump and pointer from
being damaged.
(4) Make sure that there is no concave and convex within the sliding area,
which will influence test results.
(5) In sliding length caliberation, the rubber sheet shall stop immediately
after it touches pavement, no sliding forward otherwise the caliberated
length will be over long.
(6) Friction coefficient is influenced by pavement cross section. Normally
friction coefficient is small in the center and big in two sides. Left Wheel
mark of traffic direction is the place where friction coefficent is small and
brakes are applied frequently, it represents the most disadvantageous
circumstances and is usually taken for testing points.
(7) New rubber sheet shall be tested on dried pavement for 10 times, and
20 times on wet pavement before application. Abrasion of long edge
rubber sheet is no more than 3.2mm, and short edge is no more than
1.6mm. Besides, oil polluted rubber sheet is not suitable for application.
Validity of rubber sheet is one year period.
V.Maintenance
(1) Skid Resistance Tester is kind of precision instrument, its
structure and parts shall be well protected. Read manual carefully before
testing, and operate strictly according to the manual.
(2) The apparatus shall be cleaned after testing finish. The case shall be
placed in a room which is dry and well ventilated.
(3) The apparatus shall be placed in the case after testing finished. Over
viberation and sudden impaction is not allowed in assemble and
transportation.
Audited Supplier 
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