The presentation gives information about the Taylor-Hobson Roughness Tester, which is a surface finish measurer. it would increase the knowledge of the viewer.

1. ALA COMPONENT
TOPIC: The Taylor-Hobson Roughness Tester
Submitted By: Submitted To:
Nishant Mathar(170410119058) Prof. Sagar S. Jani
Raj Meghani(170410119059)
Bhargav Mistry(170410119060)
Nishant Narvekar(170410119061)

2. The Taylor-Hobson Roughness Tester
This instrument is a stylus and skid type of
instrument working on carrier modulating
principle. The variation in the surface profile is
sensed by the probe, which is attached to the
armature.
The gap between the armature and E-shaped
arm varies according to the surface profile and
due to this amplitude of the AC current flowing
in the coil is modulated.

3. Construction
As showen in figure(in next slide), the
stylus is mounted on the armeture, which
is pivoted at the central limb of an E-
shaped soft iorn head.
The outer limbs of the head are provided
with two induction coils and a small air
gap between the armeture and outer
limbs of the head.

4. Schematic Diagram of Taylor-Hobson
Roughness Tester

5. Working
A downword movement of the stylus results in
decreasing the air gap of the primary coil and in an
equal increase of the air gap at the secondary coil.
 Thus the amplitude of the original A.C. current flowing
in the coil is modulated
 The output of the bridge thus consist o9f modulation
only.

6. This is further demodulated so that
the current now is directly propotional
to the vertical displacement of the
stylus only.
The demodulated output is caused to
operate a pen recorder to produce a
permanent record and the meter to
give a numerical assessment directly.

7. Advantages
Any desired roughness parameter can be obtained
Higher accuracy is obtained in measurement
Ultra precision measurements can be obtained
Simple processing electronics elements
Proven technology

8. Disadvantages
Bulky & complex
Relatively fragile
High initial cost
Needs skilled operators

11. THANK YOU