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

General Description
This option consists of special leadwires, either added to open-faced gages, or substituted for lead ribbons on WA-, WK-, or WD-Series gages. The wire is very formable, and may be spot-welded or soldered to main leadwires. The primary advantages are easy handling and excellent resistance to oxidation at the highest temperature the gages can withstand.

Leads
0.8 in (20 mm) long nickel-clad copper wires 0.005 in (0.13 mm) diameter. For some gage types, usually small patterns, wire size must be reduced to 0.0035 in (0.09 mm) diameter.

Solder
EA- , ED- , EK- , EP-Series gages: +430° F (+220° C) tin-silver alloy; WA-Series gages: +570° F (+300° C) lead-tin-silver alloy; WK and WD-Series gages: +770° F (+410° C) solder.

Temperature Limit
E-backed gages: +400° F (+200° C); WA-Series gages: +500° F (+260° C); WK- and WD-Series: +750° F (+400° C).

Fatigue Life
Fatigue life will normally be degraded by Option SP30. This occurs primarily because the copper wire has limited cyclic endurance. Option SP30 should therefore not be used when best fatigue life is required, unless the tab area of the gage is in a low strain area ( + 1000 microstrain or less). Loss of cyclic endurance is experienced particularly with WA- , WK- , and WD-Series gages.

Size
Matrix size is unchanged. On W-backed gages, SP30 leads are substituted for the normal beryllium copper ribbon leads. One wire lead per tab is supplied.

Strain Range
Option SP30 normally reduces the strain range of E-backed gages but does nor similarly affect W-backed gages.

Flexibility
E-backed gages with Option SP30 leads are not as conformable as standard gages. W-backed gages are not affected.

Resistance Tolerance
Not affected.

Reference Table