New Vishay Micro-Measurements high-temperature weldable strain gages

Citation

(2004), "New Vishay Micro-Measurements high-temperature weldable strain gages", Sensor Review, Vol. 24 No. 2. https://doi.org/10.1108/sr.2004.08724bad.001

New Vishay Micro-Measurements high-temperature weldable strain gages

New Vishay Micro-Measurements high-temperature weldable strain gages

Keywords: Vishay, High temperature, Gauge, Strain

Vishay Intertechnology, Inc. has released a new series of high-temperature weldable strain gages optimized for high-temperature testing applications, such as stress analysis (Plate 1). They offer easy installation, high resistance to fatigue, and temperature rating up to 980°C (1,800°F).

Plate 1 The M-series and F-series leadwires from Vishay

The new strain gages from Vishay Micro- Measurements are free-filament wire strain gages that have been pre-bonded to shim stock with flame-sprayed alumina. As a result, the new gages are easy to install in the field, especially on large structures, through welding to the test structure with a capacitive discharge spot welder such as Vishay's Model 700.

With a bonded wire design that resists fatigue, the new high-temperature weldable strain gages are an excellent choice for dynamic, impact, or vibratory strain measurements. While designed primarily for dynamic measurement applications, the active dummy method of temperature compensation can be used when static strain measurements are taken.

The gages are available in four options, with a choice of Nichrome V or Pt8W sensor alloys and either of the two types of pre-attached, high-temperature, insulated cable: M-Series or F-Series.

Gages with M-Series leadwires consist of a free-filament gage bonded to a shim with an integral high-temperature cable with chromel/ alumel wires. The new high-temperature weldable strain gages are best suited for high- temperature applications in which protection against moisture is not required, however, each M-series gage features a mineral-insulated, two- conductor cable with an Inconel metal jacket that offers excellent protection in harsh environments and a temperature rating up to 980°C (1,800°F). The ends of the gage are sealed to avoid moisture absorption during shipping or storage.

Gages with F-series leadwires consist of a free-filament gage bonded to a shim, a weldable transition terminal, and a high-temperature cable with chromel/alumel wire. A fiberglass- insulated, braided, two-conductor cable assembly is attached at the gage end through alumina insulators strapped to the terminal shim, providing a firm anchor for the cable at the gage end. The cable conductors are threaded through lengthwise holes in the alumina insulators and bonded to the insulators with high-strength ceramic cement to prevent wire movement at the gage-cable weld junction. The flexible fiberglass cable is rated to 650°C (1200°F) and provides reliable performance in installations where fraying due to vibration is not a concern.

All four gage configurations feature nominal resistance of 120 Ω, a sensor gage length of 0.25 in., a shim length of 0.50 in., and a shim width of 0.30 in.

Production quantities of the new strain gages are available currently.