The Dakota Ultrasonics BT1-DL (TI-MINIMAX) Bolt Tension Monitor Meter Z-182-0002 / Z-156-0008 Extensometer, is a state of the art instrument designed to measure elongation produced by tightening a threaded fastener. The Dakota Ultrasonics BT1-DL (TI-MINIMAX) Bolt Tension Monitor Meter Z-182-0002 / Z-156-0008 Extensometer can measure the elongation very accurately in fasteners of virtually any material from 1/2 inch to 4 feet in length. The measurement is achieved by determining the change in the transit time of an ultrasonic shock wave along the length of the fastener as the fastener is tightened by any method. The on-board microcomputer automatically interprets this time measurement to display the time(nanoseconds), elongation, load, stress, or %strain from stretching a fastener.
Also known as Z-156-0006, Z-156-0002.
Probes/Transducers and Calibration blocks are sold separately
| Part Number Z-156-0008 | Dakota BT1-DL Bolt Tension Monitor (MiniMax) |
| Certificate | ![]() |
| Display Mode | |
| Material thickness digits display | ![]() |
| A-Scan | Rectified (half wave view), or RF (full waveform view) |
| Measurement Range | PE - 25.4 - 25,400mm (1 - 999") |
| Resolution | 0.001mm (0.0001") or 0.0001mm (0.00001") switchable |
| Measurement Rate | |
| Manual | 8 readings per second |
| Velocity Calibration Range | 1250 - 13,995m/s (0.0492 - 0.5510 in/s) |
| Temperature Compensation | ![]() |
| Limit Alarm Mode | ![]() |
| Memory and Data Logging | 4GB internal memory Sequential and grid batching Bitmap graphic capture and capture viewer |
| Calibration Options | Automatic, fixed, single and two-point |
| Transducer Probe Type | Single element |
| Transducer Frequency Range | 1 - 10MHz |
| Display | 1/8" VGA greyscale display (240 x 160 pixels) Viewable area 62 x 45.7mm (2.4 x 1.8") |
| Units (Selectable) | in/mm, s, F/C |
| LED Backlight | On / Off/ Auto |
| Repeatability / Stability Indicator | ![]() |
| Low Battery Indicator | ![]() |
| Battery Save Mode | Auto |
| Transducer Connector Type | Microdot, Lemo and BNC |
| USB-C Interface | ![]() |
| Temperature Sensor | 5 pin LEMO 1 |
| Screen Refresh Rate | 30 Hz |
| Timing | Precision TCXO timing with single shot 100 MHz 8 bit ultra-low power digitizer |
| Pulser Type | Square Wave. Selectable 100, 150 and 200 volts. Selectable options Spike, Thin, and Wide. 80 to 400ns |
| Damping | 50, 75, 100, 300, 600, & 1500ohms |
| Frequency Band | Broadband 1.8 - 19 MHz (-3dB) filter |
| Horizontal Linearity | 0.4% FSW |
| Vertical Linearity | 1% FSH |
| Amplifier Linearity | 1 dB |
| Amplitude Measurement | 0 to 100% FSH, with 1% resolution |
| Delay | 25,400 mm (0 - 999.9") at steel velocity |
| Measurement Gate | One gate with audible and visual alarm. Amplitude 5-95%, 1% steps |
| Setups | 64 custom user defined setups; factory setups can also be edited by the user |
| Auto Set | Automates the detection, scope, and display setting process for each individual bolt |
| Alarm Limits | Adjustable Hi/Low tolerances with visual LED's and audible beeper |
| Field Calibration | Vector or Regression correction curve for increased accuracy using Load & Stress |
| Alarm Limits Bar | Hi & Lo alarm limits for displaying an acceptable tolerance range |
| Detections | Zero Crossing |
| Time | Nanoseconds |
| Elongation | Change in length (in/mm) |
| Load | Force load applied (pounds KIP, or megapascals MPa) |
| Stress | Force for unit area stress applied (inches per inch or millimeters per millimeter) |
| %Strain | Ratio of elongation to effective length |
| Bolt Materials | Select types from a preset or custom list |
| Glue-On | Available for short bolts with minimal/short elongations to eliminate transducer placement errors |
| Part Number Z-156-0008 | Dakota BT1-DL Bolt Tension Monitor (MiniMax) |
| Operating Temperature | -10 to 60C (14 to 140F) |
| Power Supply | 3 x AA batteries and via USB |
| Battery Life | Alkaline 35 hrs, Nicad 10 hrs, NI-MH 35 hrs |
| Gauge Weight | 383g (13.5oz) - including batteries |
| Gauge Dimensions | 63.5 x 165 x 31.5mm (2.5 x 6.5 x 1.24") |
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| Dakota Ultrasonics BT1-DL (TI-MINIMAX) Bolt Tension Monitor Meter Z-182-0002 / Z-156-0008 - Instruction Manual |
| Dakota Ultrasonics TI-MINIMAX Bolt Tension Monitor Meter Z-182-0002 Extensometer - Data Sheet |