The SPTMAN by James Fisher Testing Services is an easy to use and portable system that is used to calculate hammer energy.
The SPTMAN system measures the actual energy transferred from the drive hammer to the drive rods and calculates the hammer energy coefficient by comparison with the theoretical potential energy.
The heart of the system is a rugged, portable analyser with solid state memory. The system is supplied with a standard 54mm diameter instrumented SPT rod, as well as a waterproof carry case for added protection.
Tests are carried out using as easy to follow menu display which enables hammer energy and energy ration to be displayed in real-time.
System service and calibration
The measurement of SPT hammer energy is now recommended for all Standard Penetrometer Test (SPT) systems.
BS EN ISO 22476-3 states that the hammer energy ratio has to be known and have a certificate of calibration available if N values are going to be used for the quantitative evaluation of foundations or for the comparison of results.
This standard also recommends that checks should be carried out on a six monthly basis. JFTS recommends that it is also good practice to carry out a calibration at the start of any large contract. Follow the link to our SPT hammer calibration service page for more information.
Benefits of the SPTMAN hammer energy tester:
- Instant hammer energy measurement and transfer coefficient calculation
- Rugged and lightweight system
- Storage for over 700 results
- Complies with the relevant parts of both BS EN ISO 22476-3 and ASTM D 4633-10
- Backlit LCD screen for working in dark environments
- James Fisher Testing Services' calibration service available
All of our equipment is supplied fully calibrated to UK national standards.
|SPTMAN system specifications|
|Features||On-site energy measurement
Standard energy check unit included for on-site verification
Daylight viewable screen
Rugged lightweight unit with waterproof connectors
Tactile large keys for operating with gloves
Low power with long battery life
Flash memory for instant start up and power down
|Keypad||Sealed colour coded and full alphanumeric keypad, tactile and audio feedback|
|Operating temperature||0 to +50°C|
|Display||Monochrome LCD transflective with backlight
Contrast keypad adjustable
Display area 122mm x 77mm
Protective anti-reflective glass
|Acquisition||2 channel, 16 bit acquisition at 100KHz sample rate
Pre-trigger on both channels, auto ranging gain feature
|Frequency range||0Hz to 5000Hz|
|Storage||700+ results, 3 data sets per pile with full header information including site, test no, drop height, drop weight and date/time stamp|
|Display||Acceleration v time
Force v time
Energy measurement as % of theoretical
|Accuracy||± 2% of hammer energy|
|Power||Battery: 1.2V NiMH rechargeable AA cells
Auto power off and battery indicator
|Battery life||8 hours + operation on full charge|
|Charge time||Approx 6 hours|
|Charging||External wall plug-in charger for 100/110/250VAC inputs (trickle charge)
External cigar plug-in charger for 12VDC inputs (fast charge)
|Dimensions||L 218mm x W 187mm x D 55mm|
|Type||To suit clients requirements - normally BW/NW/AW|
|Length||Dependent on diameter - typically 1m|
|Accelerometers||2No 10000g 'shock' type with ICP power supply|
|Strain gauge type||Foil|
|Connection||3m fly leads with rugged bayonet connectors|
The SPTMAN analysis software is supplied as standard, and adapts a user friendly, Windows based platform for downloading data, analysing results and producing calibration certificates.
The certificate includes plots of force, velocity, acceleration and displacement; as well as measured energy, theoretical energy and energy ratio. Full details of the rig and site can also be shown.
The SPT hammer energy measurement method is based on the propagation of waves in long elastic cylinders. When the SPT rod is struck with a falling weight, the rod section is deformed (enlarged) and this enlargement travels down the pile to the base of the rod where it is reflected back.
The force transmitted to the rods is calculated by measuring the axial strain in the rod over a period of time and taking the modulus and cross section of the rod into account by:
F(t) = Aa x Ea x εm(t)
The particle velocity of the measurement section is determined by integrating data from the accelerometers over a period of time. The energy which passes into the drive rods can be determined from the force and velocity data using:
E(t') = t∫0 F (t) v (t) dt