Lunometer - How it Works

Instructions for using a Lunometer®

Throughout this instruction document, the word "Sample" will be used to describe what it is you are measuring. This could be woven cloth, woven metal screening, or other materials.

Your Lunometer® is a precision optical instrument made from either vinyl or acrylic (often referred to as Plexiglas®). This instrument can be scratched easily unless care is taken in handling it. Exposing it to temperatures above 110ºF (43ºC) or to water or solvents can result in damage that cannot be repaired.

How to Measure Cloth or Other Materials

In order to make accurate measurements, several conditions must exist:

The sample must be uniform in weave density
The sample must be spread on a flat surface, but not stretched or pulled
There must be a good light source shining on or through the sample
You must use a Lunometer with the proper measurement range

When you have taken care of these concerns, determining the thread count or screen density is fast, simple, and accurate!

Place the Lunometer flat against the sample

Rotate the Lunometer until a pattern develops as the lines on the Lunometer interact with the lines formed by the threads. The pattern will consist of an ellipse that can be brought almost to a point as the Lunometer is rotated a little in either direction.

Depending on how you orient the Lunometer, the "Point" of the pattern will be pointing to a number on either the Lines per Inch scale or the Lines per Centimeter scale. The number on the scale indicates the thread or line count. If the "Point" is between numbers, you may add a fraction (i.e., 1/2, 1/3, etc.) to the lower number. How large a fraction you use depends on how far past the number the "Point" is and how accurate your measurement needs to be. However, for most measuring applications, the closest number is sufficiently accurate.

That is all you need to do! With just a little practice, virtually anybody can obtain accurate and repeatable measurements.

Note: Measuring cloth with a printed pattern is possible, but rather difficult.

Lunometers come in the following ranges (inch/cm):
F	25–60 inch 10–23.5 cm		G	38–86 inch 15–34 cm		R	50–120 inch 19–47 cm