Can You Measure Glass Thickness Without Removing the Window?

Yes. A handheld glass thickness gauge measures glass and air space thickness in an installed insulated glass (IG) unit without removing the window. Laser gauges like EDTM's MG1500 MIG measure from a single side with no additional tools, and meters like the Glass-Chek PRO test windows already installed in the field.

How do you measure glass thickness without removing the window?

You use a gauge that reads the glass from the surface of the installed unit. The MG1500 MIG gauge uses laser reflections off the glass surfaces, which appear on its graduated scale and show the thickness of the glass and the air space between the panes. The Glass-Chek meters show the results on a display. For glass thickness measurement that also shows the type of Low-E coating, EDTM's GC3001 Glass-Chek PRO tests single, double, and triple-pane windows in production, at the job site, or already installed in the field.

How does it work in three steps?

1.    Place the tool on the installed window.

2.    Take the measurement. The MG1500 reads from a single side of the IG unit. The Glass-Chek PRO measures glass, air space, and overall IG thickness of triple-pane windows at the single push of a button.

3.    Read the result. On the MG1500, read the laser reflections against the graduated scale. On the Glass-Chek meters, read the results screens.

For the full MG1500 procedure, including zeroing the gauge, see EDTM's MIG thickness gauge guide.

Which tools measure an installed window?

If you want a glass thickness tester that also identifies laminated glass, the GC3200 Glass-Chek ELITE adds laminated glass identification and the thickness of the laminate inner layer.

Can you measure from just one side of the window?

Yes, with the MG1500, which takes its measurements from a single side of the IG unit with no additional tools. The GC3001 can also locate a Low-E coating on a double-pane window from a single side. That is an advantage in multi-story buildings, where you may only have access to the inside of the window.

Where on the window should you measure?

It depends on the tool:

•       GC3001: the GC3001 page says to take measurements at the bottom center of the window, which it describes as the most accurate and repeatable measurement location. The meter's welcome screen reminds you.

•       MG1500: the MG1500 manual says to take the air space reading near the edge of the IG assembly, close to the spacer bar, where the unit has the least deflection.

What can you measure without removing the glass?

•       Glass thickness of each pane

•       Air space between the panes

•       Overall IG thickness

•       Triple-pane assemblies

•       Laminated glass, with the detail depending on the tool

•       Low-E coating type and location, with the GC3001 and GC3200

Why measure an installed window?

Glass thickness measurement is part of ordering the correct replacement IG unit, along with the air space. Measuring the installed window helps reduce incorrect orders, which saves time and money. The tools are also used for field installation and servicing, production spot-checking, and building inspection.

Frequently asked questions

Do you need access to both sides of the window?

Not for the MG1500, which takes its measurements from a single side of the IG unit. The GC3001 can also locate a Low-E coating on a double-pane window from a single side, which helps when you only have access to the inside.

Can you measure triple-pane windows without removing them?

Yes. The MG1500 can measure triple-pane assemblies. The GC3001 and GC3200 measure glass, air space, and overall IG thickness of triple-pane windows with a single push of a button.

Can you measure laminated glass without removing it?

The MG1500 measures individual panes in a laminated assembly. The GC3001 displays the total thickness of laminated glass. The GC3200 identifies laminated glass and measures the thickness of the laminate inner layer.

Does a glass thickness tester work on tinted glass?

Yes. The GC3001 is compatible with tinted glass, and tinted glass is among the glass types listed for the MG1500.

How thick a window can the GC3001 measure?

The GC3001 Glass-Chek PRO has a thickness range of approximately 2 inches.

Can you measure double-pane windows without removing them?

Yes. The GC3001 measures single, double, and triple-pane windows in production, at the job site, or already installed in the field, and the MG1500 measures double-glazed IG units.

Can you find the Low-E coating without removing the window?

The GC3001 can locate a Low-E coating on a double-pane window from a single side, and it shows whether the coating is hard or soft. The GC3200 shows the location and type of Low-E coating.

Why measure an installed window?

Measuring the glass thickness and air space is part of ordering the correct replacement IG unit. Having the numbers helps reduce incorrect orders, which saves time and money.

Find a glass thickness gauge for installed windows

See the full range of EDTM field service glass and air space measurement tools, including every glass thickness gauge for installed windows.