Bolt strain gauge series BTM/BTMC

These gauges are used for measurement of tensile strain of bolt. They are simply inserted into pre-drilled hole in the bolt with exclusive adhesives. This method is recommendable when an ordinary strain gauges can not be mounted on the bolt surface. Accurate tensile force measurement is possible by calibrating the bolt after installing the bolt gauges.

• Single-element

  Gauge lead: polyurethane wire ø0.14, 80 mm
  * The cover on the polyurethane wire can be peeled away with a soldering iron, allowing it to be worked later.

  
  

   

  Type	Gauge length (mm)	Gauge width (mm)	Backing length (mm)	Backing width (mm)	Resistance (Ω)
  BTM-1C (Φ1.6mm)	1	0.7	5.6	1.4	120
  BTM-6C (Φ2mm)	6	1.0	12.0	1.7
  BTM-6CTA Temperature-integrated（-10 to +80℃） (Φ2mm)	6	1.0	12.0	1.7

  Each package contains 10 gauges.

• We can embed a BTM (bolt strain gauge) into any bolt.

  The way of adhering a BTM (bolt strain gauge) differs from a general strain gauge, requiring drilling of the bolt, embedding the strain gauge, and load calibration.

  Ex.) Load calibration specifics (bolt size: M10 × 1.25, L = 65)

  Load (kN)	0.0	4.6	9.2	13.8	18.4	23.0	Nonlinearity (%RO)	Calibration coefficient (kN/1×10-6)
  Indicated strain (×10-6)	0	378	747	1129	1518	1916	1.1	0.0120

  [We also embed temperature-integrated BTM (bolt gauge). Contact us for details.]

• series BTMC

  Single-element (G.F. 2.1 approx.)

  

  Type	Gauge length (mm)	Gauge center a (mm)	Backing diameter b (mm)	Resistance (Ω)	Applicable hole diameter (mm)
  BTMC-05-D10-003LE	0.5	5	Φ0.9	120	Φ1.0
  BTMC-1-D16-003LE	1	5	Φ1.5	120	Φ1.6
  BTMC-3-D20-003LE	3	10	Φ1.9	120	Φ2.0

  Each package contains 10 gauges.