How to detect thickness of A4 paper any ideas?

Projects General Guidance
1

Instrumentation System for Measuring A4 Paper Thickness

Objective:

  1. To design and develop an instrumentation system for the measurement of A4 paper thickness.
  2. To calibrate the proposed instrumentation system.
  3. To investigate the accuracy of the developed instrumentation system.
2

Welcome to the forum

You started a topic in the Uncategorised category of the forum when its description explicitly tells you not to

Your topic has been moved to a relevant category. Please be careful in future when deciding where to start new topics

1 Like
3

Maybe a hall effect sensor one side of the paper and a weak, covered magnet pressed against the paper on the other side. I have no idea if the accuracy would suit your application, though. Standard printer paper (80g/sqM) is about 120 microns thick. Maybe also something using a capacitance effect but this could be affected by the type of paper to be measured.

1 Like
4

On an industrial scale, measure the blockage of beta radiation through the paper.

Not practical for a small project, but this sounds like a school assignment and we don't know what type course it originates from.

1 Like
5

You may also be able to use a pressure sensor and a small blast of air say as the paper passes over a small cavity. An optician uses a device incorporating these elements to measure the pressure inside an eye (Tonometry) without physical contact with the eye.

6

If you need to measure whatever type of paper, different density, color, chemistry... you really need to measure physical thickness. (Digital) micrometer screw gauge is the best starting point.

1 Like
7
  1. and 2.

image
image441×338 1.85 KB

  1. Measure (a) 100 and divide by 100, (b) measure 10 and divide by 10 (c) a - b = error.
1 Like
8

Here are two ways that have been used historically to measure thickness.

20241224_0836051
20241224_08360511920×2560 284 KB

If you want to record the thickness using an Arduino, replace the manual dial indicators with an electronic one and connect to the serial port on the indicator.
Or, you can make a similar device using a 10k potentiometer as the pivot point in a par of scissors. Some assembly required.

2 Likes
9

How fast do the measurements need to be. What is the required accuracy? What is the environment like? Where is this located, on a production machine, in the lab, ???

Is this to be general in nature or do you need to check it against traceable standards?

What will this process be?

1.** Please keep in mind that we are not a free design or code-writing service. We’re more than happy to help with your design or code, but we need you to make an initial attempt. Please design and write your code, then post it along with an explanation of what’s not working properly and the annotated schematic.

10

can you share any resources related to capacitances effect to measure thickness?

11

Appreciate your answer and insights

12

I have no idea how to use any of those, can you please share any resources?

13

HI, @mdmasudkarim
Welcome to the forum.

Is this a school/college/university project?

Instead of measuring one sheet, it may be better to measure a stack of 100 sheets to give you an easier figure, then divide by 100 for the average thickness.

Tom... :smiley: :+1: :coffee: :australia:

14

Yeah, digital micrometer screw gauge can be used but maybe this one for job but I want to build one with sensor maybe with something like IR sensor or optical solutions

15

Thanks, this is a personal project, I'm trying to find out how much sheet I have, first I thought about just measure the total weight and then divide by the weight of single sheet, now I'm searching for something that can maybe find one sheet thickness/100 sheet thickness

16

thanks for your reply, can you please elaborate the picture how do you calibrate and measure?

17

Thanks, love that idea. Maybe I will try with the 10K pot as the pivot point in a par of scissors, any idea where to start with?

18

Sure. make a working scissors using any old pot. Get the mechanical part working first.

1 Like
19
  1. How fast do the measurements need to be. What is the required accuracy? What is the environment like? Where is this located, on a production machine, in the lab, ???
    -- I'm not sure, but trying to do implement for paper binding system (mini business), the accuracy is the catch, cause one sheet thickness is very small, and I don't want to lose/miss 5-10 sheet per bundle.
  2. Is this to be general in nature or do you need to check it against traceable standards?
    -- is there any standard or current system that can detect the thickness of paper sheet with sensor not using any gauge? is there any standards available?
20

The top device will be mounted on a stepper-motor-driven screw with a feeler/switch on the tip. The motor will be configured for the smallest microstep. The pitch of the screw (threads spacing) is known. Count the steps. The distance traveled is a product of steps taken and steps per pitch. Measure 100 sheets and divide by 100 for "1of100" sheets. Measure 10 sheets and divide by 10 for "1of10" sheets. The error in measurement will be the difference of "1of100" and "1of10"

You should have lead with this. My idea for a practical thickness measure with rudimentary devices, is stupid in concept and practice in this context.

1 Like