Series Availability
EA , EP , WA , ED , WD , EK , WK

General Description
This option provides encapsulation, and thin, printed circuit terminals at the tab end of the gage. Beryllium copper jumpers connect the terminals to the gage tabs. The terminals are 1.4 mil [0.0014 in (0.036 mm)] thick copper on polyimide backing nominally 1.5 mils [0.0015 in (0.038 mm)] thick. Option W gages are rugged and well protected, and permit the direct attachment of larger leadwires than would be possible with open-faced gages. This option is primarily used on EA Series gages for general-purpose applications.

Solder
+430 deg F (+220 deg C) tin-silver alloy solder joints on E-backed gages, +570 deg F (+300 deg C) lead-tin-silver alloy solder joints on W-backed gages.

Temperature Limit
+350° F (+175° C) for E-backed gages, +450° F (+230° C) for W-backed gages.

Grid Protection
Entire grid and part of terminals are encapsulated with polyimide.

Fatigue Life
Some loss in fatigue life unless strain levels at the terminal location are below + 1000microstrain.

Size
Option W extends from the soldering tab end of the gages and thereby increases gage size. With some patterns, width is slightly greater.

Strain Range
With some gage series, notably E-backed gages, strain range will be reduced. This effect is greatest with EP Gages , and Option W should be avoided with them if possible.

Flexibility
Option W adds encapsulation, making gages slightly thicker and stiffer. Conformance to curved surfaces will be somewhat reduced. In the terminal area itself, stiffness is markedly increased.

Resistance Tolerance
On E-backed gages, resistance tolerance is normally doubled.

Reference Table