How to Calculate and Solve for Strain Gauge Factor | Instrumentation

Last Updated on April 24, 2024

The image above represents the strain gauge factor. To calculate the strain gauge factor, four essential parameters are needed, and these parameters are the Change in Resistance of the Strain Gauge (ΔR), Resistance of the Strain Gauge (R), Change in Length of the Strain Gauge (ΔL) and Initial Length of the Strain Gauge (L).

The formula for calculating strain gauge factor:

G_F = ^LΔR / _RΔL

Where:

G_F = Strain Gauge Factor
ΔR = Change in Resistance of the Strain gauge
R = Resistance of the Strain Gauge
ΔL = Change in Length of the Strain Gauge
L = Initial length of the strain Gauge

Let’s solve an example;
Find the strain gauge factor when the change in resistance of the strain gauge is 12, the resistance of the strain gauge is 14, the change in length of the strain gauge is 16, and the initial length of the strain gauge is 10.

This implies that;

ΔR = Change in Resistance of the Strain gauge = 12
R = Resistance of the Strain Gauge = 14
ΔL = Change in Length of the Strain Gauge = 16
L = Initial length of the strain Gauge = 10

G_F = ^LΔR / _RΔL
That is, G_F = ^{10 x 12} / _{14 x 16}
G_F = ¹²⁰ / ₂₂₄
G_F = 0.535

Therefore, the strain gauge factor is 0.535.

Calculating for Change in Resistance of the Strain Gauge when the Strain Gauge Factor, the Resistance of the Strain Gauge, the Change in Length of the Strain Gauge and the Initial Length of the Strain Gauge are Given

ΔR = ^{G_F x RΔL} / _L

Where;

ΔR = Change in Resistance of the Strain gauge
G_F = Strain Gauge Factor
R = Resistance of the Strain Gauge
ΔL = Change in Length of the Strain Gauge
L = Initial length of the strain Gauge

Let’s solve an example;
Find the change in resistance of the strain gauge when the strain gauge factor is 20, the resistance of the strain gauge is 18, the change in length of the strain gauge is 14, and the initial length of the strain gauge is 10.

This implies that;

G_F = Strain Gauge Factor = 20
R = Resistance of the Strain Gauge = 18
ΔL = Change in Length of the Strain Gauge = 14
L = Initial length of the strain Gauge = 10

ΔR = ^{G_F x RΔL} / _L
ΔR = ^{20 x (18)(14)} / ₁₀
Then, ΔR = ^{20 x 252} / ₁₀
ΔR = ⁵⁰⁴⁰ / ₁₀
ΔR = 504

Therefore, the change in resistance of the strain gauge is 504.

Read more: How to Calculate and Solve for Resistance of a Strain Guage Wire | Instrumentation

Calculating for Resistance of the Strain Gauge when the Strain Gauge Factor, the Change in Resistance of the Strain Gauge, the Change in Length of the Strain Gauge and the Initial Length of the Strain Gauge is Given

R = ^LΔR / _{GF x ΔL}

Where;

R = Resistance of the Strain Gauge
G_F = Strain Gauge Factor
ΔR = Change in Resistance of the Strain gauge
ΔL = Change in Length of the Strain Gauge
L = Initial length of the strain Gauge

Let’s solve an example;
Find the resistance of the strain gauge when the strain gauge factor is 14, the change in resistance of the strain gauge is 7, the change in length of the strain gauge is 2, and the initial length of the strain gauge is 4.

This implies that;

G_F = Strain Gauge Factor = 14
ΔR = Change in Resistance of the Strain gauge = 7
ΔL = Change in Length of the Strain Gauge = 2
L = Initial length of the strain Gauge = 4

R = ^LΔR / _{GF x ΔL}
That is, R = ⁽⁴⁾⁽⁷⁾ / _{14 x 4}
R = ²⁸ / ₅₆
R = 0.5

Therefore, the resistance of the strain gauge is 0.5.

Calculating for Change in Length of the Strain Gauge when the Strain Gauge Factor, the Change in Resistance of the Strain Gauge, the Resistance of the Strain Gauge and the Initial Length of the Strain Gauge are Given

ΔL = ^LΔR / _{GF x R}

Where;

ΔL = Change in Length of the Strain Gauge
G_F = Strain Gauge Factor
ΔR = Change in Resistance of the Strain gauge
R = Resistance of the Strain Gauge
L = Initial length of the strain Gauge

Let’s solve an example;
Find the change in length of the strain gauge when the strain gauge factor is 8, the change in resistance of the strain gauge is 3, the resistance of the strain gauge is 2, and the initial length of the strain gauge is 10.

This implies that;

G_F = Strain Gauge Factor = 8
ΔR = Change in Resistance of the Strain gauge = 3
R = Resistance of the Strain Gauge = 2
L = Initial length of the strain Gauge = 10

ΔL = ^LΔR / _{GF x R}
So, ΔL = ^(10)(3) / _{8 x 2}
ΔL = ³⁰ / ₁₆
ΔL = 1.875

Therefore, the change in length of the strain gauge is 1.875.

Calculating for the Initial Length of the Strain Gauge when the Strain Gauge Factor, the Change in Resistance of the Strain Gauge, the Resistance of the Strain Gauge and Change in Length of the Strain Gauge are Given

L = ^{G_F x RΔL} / _ΔR

Where;

L = Initial length of the strain Gauge
G_F = Strain Gauge Factor
ΔR = Change in Resistance of the Strain gauge
R = Resistance of the Strain Gauge
ΔL = Change in Length of the Strain Gauge

Let’s solve an example;
Find the initial length of the strain gauge when the strain gauge factor is 15, the change in resistance of the strain gauge is 12, the resistance of the strain gauge is 6, and the change in length of the strain gauge is 4.

This implies that;

G_F = Strain Gauge Factor = 15
ΔR = Change in Resistance of the Strain gauge = 12
R = Resistance of the Strain Gauge = 6
ΔL = Change in Length of the Strain Gauge = 4

L = ^{G_F x RΔL} / _ΔR
L = ^{15 x (6)(4)} / ₁₂
So, L = ^{15 x 24} / ₁₂
L = ³⁶⁰ / ₁₂
L = 30

Therefore, the initial length of the strain gauge is 30.

How to Calculate and Solve for Strain Gauge Factor With Nickzom Calculator

Nickzom Calculator – The Calculator Encyclopedia is capable of calculating the strain gauge factor.

To get the answer and workings of the strain gauge factor, use the Nickzom Calculator – The Calculator Encyclopedia. First, you need to obtain the app.

You can get this app via any of these means:

Web – https://www.nickzom.org/calculator-plus

To get access to the professional version via web, you need to register and subscribe for NGN 2,000 per annum to have utter access to all functionalities.
You can also try the demo version via https://www.nickzom.org/calculator

Android (Paid) – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator
Android (Free) – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator
Apple (Paid) – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8
Once, you have obtained the calculator encyclopedia app, proceed to the Calculator Map, then click on Materials and Metallurgical under Engineering.

Then, Click on instrumentation under Materials and Metallurgical

Now, Click on Strain Gauge Factor under Instrumentation

The screenshot below displays the page or activity to enter your values, to get the answer for the strain gauge factor according to the respective parameters which is the Change in Resistance of the Strain Gauge (ΔR), Resistance of the Strain Gauge (R), Change in Length of the Strain Gauge (ΔL) and Initial Length of the Strain Gauge (L).

Now, enter the values appropriately and accordingly for the parameters as required by the Change in Resistance of the Strain Gauge (ΔR) is 12, Resistance of the Strain Gauge (R) is 14, Change in Length of the Strain Gauge (ΔL) is 16 and Initial Length of the Strain Gauge (L) is 10.

Finally, Click on Calculate

As you can see from the screenshot above, Nickzom Calculator– The Calculator Encyclopedia can calculate the strain gauge factor and it also presents the formula, workings and steps too.