Bolt Stress Measurement - Mini-MAX-Series Ultrasonic Bolt Meter - Bolting System

Bolt Stress Measurement - Mini-MAX-Series Ultrasonic Bolt Meter - Bolting System

The MINI-MAX, Ultrasonic Bolt Tension Monitor, defines the state of the art in the measurement of the actual elongation produced by tightening a threaded fastener. The MINI-MAX 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. Through the use of high speed digital signal processing and automated diagnostics, the MINI-MAX minimizes the requirement for extensive operator training. With built in data recordation and reporting through an RS232 interface, the MNI-MAX offers an easy to use and reliable solution to the most difficult bolting problem.

Specifications for Bolt Stress Measurement - Mini-MAX-Series Ultrasonic Bolt Meter - Bolting System:


  • The first cost effective ultrasonic solution available on the market.
  • Effectively monitor your bolts during periodic shutdowns over the service life of the fastener.
  • Visually compare the unloaded to the loaded waveform.
  • Measurement quanities - Time (nanoseconds), Elongation, Load, Stress, and %Strain.
  • Display Options - RF, Rectified, Large Digits with Limits Bar.
  • Display Resolution - 1/8" VGA 240 x 160 pixels.
  • Stores 8000 readings and waveforms in multiple groups.
  • Built-in Linear regression or vector for optimizing load measurements.
  • The Auto Set feature automatically optimizes detection and adjusts display.
  • Hi/Lo alarm tolerance limits work in conjunction with the data port and external pump shut-off device.

Typical Questions/Answers on application:

  1. What are the bolts made of?
    A ferrous bolt like steel will use a magnetic Transducer. A non-ferrous bolt like aluminum will use a non-magnetic Transducer)
  2. How long are the bolts?
    Any bolt under 1 inch or 25 mm cannot be tested
  3. How wide are the bolt heads?
    If a bolt head is ¼ inch wide them a ½ inch wide transducer would not work, a ¼ inch bolt head will require a ¼ inch Transducer There can be no overhang of the Transducer on the bolt head.
  4. Is the bolt pointed or flat at the end opposite to the bolt head?
    A pointed bolt end cannot be tested. It will have to be ground flat
  5. Are there any raised lettering or numbers on the tops of the bolt heads?
    Any raised lettering or numbers will have to be ground flat
  6. Are there any recessed letters or numbers on the tops of the bolt heads?
    Any recessed letters or numbers can be filled in with coupling gel
  7. Will you be testing the same bolt more than one time, like on an assembly? Even in the same day, week, month or year?
    If you are not testing the same bolt more than one time you do not need the Temperature Sensor. If you are testing the same bolt more than one time they will need the Temperature Sensor which will need to be installed at the factory before shipping. Ambient temperature in a room or outside will affect the tension on the bolt. In the morning when the temperature is cooler inside a room or even outside, the tension will be different than in the afternoon when it is hotter latter in the day. The Temperature Sensor is needed to compensate for the ambient temperature factor. It is very important. Part # Z-156-002 is with a connection (factory installed) into the display module for the Temperature Sensor. This connection has to be done on the instrument when you purchase Temperature Sensor.



Width (2.5in/63.5 mm)
Height (6.5 in/165 mm)
Depth (1.24 in/31.5 mm)

Weight: 13.5 ounces (with batteries).

Keyboard: Membrane switch pad with twelve tactile keys.

Operating Temperature: 14 to 140F (-10C to 60C)

Case: Extruded aluminum body with nickel-plated aluminum end caps (gasket sealed).

Data Output: Bi-directional RS232 serial port. Windows® PC interface software.

Display: 1/8in VGA grayscale display (240 x 160 pixels). Viewable area 2.4 x 1.8in (62 x 45.7mm). EL backlit (on/off/auto).

Ultrasonic Specifications Measurement Modes:

Pulse-Echo (standard)
Pulse-Echo w/Gate (fine adjust)

Pulser: Square wave pulser with adjustable pulse width (spike, thin, wide).

Receiver: Manual or Auto Set gain control with 40dB range.

Timing: 10 bit 250 MHz digitizer.

Warranty: 2 year limited

Power Source: Three 1.5V alkaline or 1.2V NiCad AA cells. Typically operates for 150 hours on alkaline and 100 hours on NiCad (charger not included.)

Auto power off if idle 5 min.

Battery status icon.

Measuring Range: From 1” to 48” (25.4mm to 122cm) bolts.

Time - Nanoseconds.

Elongation - Change in length (inches/millimeters).

Load - Force load applied (pounds kIP or kN Killonewtons).

Stress - Force for unit area stress applied (pounds kPSI or megapascals MPa).

Strain % - percentage strain applied (inches per inch or millimeters per millimeter)

Resolution: +/- .00001 inches (0.0001 mm)

Velocity Range:

.0492 to .3936 in/ms
1250 to 9999 meters/sec

Fixed, Single, and Two point zero calibration options.

Select bolt material types from a preset or custom list.

Units: English & Metric / Fahrenheit & Centigrade.

Display: A-Scan - Rectified +/- (half wave view), or RF (full waveform view). Large Digits - Display and toggle between nanoseconds, elongation, load, stress, and strain.
Digit Height: 0.400 in (10mm).

Limits Bar(alarm limits) - Set Hi & Lo alarm limits for displaying an acceptable tolerance range. Repeatability Bar Graph - Bar graph indicates stability of measurement.

Data Logger (Internal) Total of 8,000 readings, multiple bolt groups. Stores both waveform views, nanoseconds, elongation, load, stress, and strain for each reading.

Memory: 16 megabit non-volatile ram.

Transducer Types: Single Element (1 to 10 MHz & 1/8” to 1” diameters).

Locking quick disconnect “00” LEMO connectors.

Standard 10 foot cable.

Custom transducers and cable lengths available on request.

Temperature probe for automatic temperature compensation.


Setups: 64 custom user defined setups. Factory setups can also be edited by the user.

Gate: Gate used to fine adjust where the detection point occurs.

Alarm Limits: Set hi and lo tolerances with audible beeper, viewable scan bar, and visual LEDs.

Auto Set: Locates the detection signal, optimizes the gain setting, and adjusts the overall display to show the waveform and detection point automatically.

Field Calibration:

Vector & linear regression.
Factory calibration traceable to national standards.


For more information about Ultrasonic Bolt Meter - Bolting System - Mini-MAX-Series , please call us at 1.877.884.8378 or Click the button below.

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