Workshop on Micrometry using Foldscope

A workshop named” Magnify Your Curiosity-Mathematics in a Laboratory with Foldscope” was organized by Department of Environmental Science, University of Calcutta on 12th March 2019 at Gramya Hitakari Girls School, Howrah, West Bengal, India in collaboration with Howrah Vigyan Chetna Samannaya.

Map showing the route of Gramya Hitakari Girls School, Howrah, West Bengal, India

Introductory Session-

The workshop started with Dr.punarbasu Chaudhuri delivering a speech on Relative Size of Things and metric conversion of different units of length.

Introductory speech by Dr. Punarbasu Chaudhuri
Workshop on foldscope, at Gramya Hitakari Girls School, Howrah, West Bengal, India
Dr. Punarbasu Chaudhuri delivering a brief idea about units of length

Introducing the macroscopic measuring tools-

After the introductory session, Dr. Punarbasu Chaudhuri demonstrated different length measuring devices such as Measuring tape, Ruler Scale, Vernier Scale, Screw Gauge their applications and limitations too.

Demonstration of Vernier Calipers to the participants
Ranjan demonstrating foldscope to the participants

Measurement session-

In this session, participants were asked to measure the thickness of their hair with a ruler scale. The measurement was done by coiling a single strand of hair around a plastic refill and measuring the total breadth. After this, the total length measured by ruler was divided by the total number of coils to get the value of a single hair strand.

Participants observing with foldscope
Participants observing hair strand under foldscope

Measurement of single hair strand using foldscope-

In this session, Stage Micrometer was introduced to the participants and by calibrating stage micrometre with a ruler scale (centimetre scale) we determined the width of a single strand of hair. It was also done at various portion of hair to get the range of the width of human hair.

Dr. Punarbasu Chaudhuri demonstrating calibration of stage micrometer with a
centimeter scale
Single strand of hair under foldscope

Measurement of stomata-

A fresh leaf peel was taken on a slide and the length and breadth of stomata were measured using foldscope.

Measurement of stomata with ruler scale after calibration using stage micrometer


During measurement using foldscope, the original images taken by smartphones has to be original images captured from a single device and not zoomed or cropped image.


This was their first exposure to micrometry using foldscope and the event was a success.

4 Comments Add yours

    1. Punarbasu says:

      Thank you for your encouraging words.

  1. Manu Prakash says:

    Beautiful work. Thanks for infusing quantitative ideas into the students from the very beginning.

    I love the smile on student faces when they first use the tool. Can’t wait to read posts from the students themselves.


    1. Punarbasu says:

      Thank you so much. We will try to get the feedback from the students as you have mentioned.

Leave a Reply