Author Archives: Andy Maslin

Want to check on the accuracy of your seismograph(s)?

We will have your seismograph’s accuracy and linearity checked against National & International Standards by an international accredited laboratory.

The laboratory is accredited to ISO 17025 for vibration meter calibration (Velocity). This guarantees technical competence and quality of service. The accreditation has been awarded by ENAC (National Accreditation Organization), an organization recognized by the ILAC (International Laboratory Accreditation Cooperation).

Call us for more information or a quotation.

Accudata GVM-1 Customer Feedback

It is two and a half years since the launch of the Accudata GVM-1 and it has been a great addition to our rental fleet.

Our customers have been very positive in their comments.  They have told us that other data-logging seismographs that they’ve used are very often difficult to download and/or make a connection with.  We designed out the possibilities of ever having problems of connection and download because the Accudata GVM-1 automatically saves every event to an SD card.  The card is simply unplugged from the GVM-1 and plugged into a computer whereupon a dialogue box opens showing all the files.

Rental clients, who are mainly concerned with measuring ground-borne vibration arising from civil engineering activities appreciate the fact that the Accudata GVM-1 is a dedicated ground vibration monitor and not a blast monitor with a secondary continuous monitoring function, that in certain manufacturer’s instruments appears to have been added as an afterthought!

The GVM-1 was designed for extreme ease of use so that anyone would be able to use it without recourse to reading an instruction manual.  The clear, bright, high resolution colour touch screen operates in a very similar way to that of a bank’s ‘hole in the wall’ cash dispenser.  After pressing the On button, the screen presents the user with five very obvious options, as well as showing the date and time and four icons along the top to indicate the status of the instrument, including a battery condition indicator and one showing that an SD card is fitted.  The first option is Start Recording!

Unlike some other seismographs, the Accudata GVM-1 has no ambiguous choices in the set-up functions meaning that a user will feel comfortable that they are using the instrument correctly.  For rental clients who very often may never have seen a seismograph before, this ease of use is a great help to them.  Our clients tell us that the Accudata GVM-1 is by far the easiest seismograph to use.

The Accudata GVM-1 is probably peerless in its accuracy

The Accudata GVM-1 Seismograph is one of the world’s most accurate vibration monitors designed to monitor ground-borne vibration in full compliance with BS5228-2:2009+A1:2014.

The Accudata GVM-1 will record values of PPV from 0.03mm/s-1 up to 140mm/s-1 between 4Hz and 128Hz with a resolution of 0.01mm/s-1.

The linearity in each axis between 4Hz and 128Hz is extremely flat (as may be seen in the graph). Accuracy below 50Hz is of paramount importance when complying with British and International Standards.  We at Accudata believe that the GVM-1 is far superior in its accuracy than very many other instruments currently available.

After manufacture, the new Accudata GVM-1 instruments are adjusted for accuracy using a laser doppler vibrometer, vibration controller, power amplifier, shaker, reference accelerometer and associated equipment. A graph of response is created for each new instrument – see below.

The European testing laboratory that undertakes the adjustment of all new Accudata GVM-1s has (as of December 2014) been awarded ILAC accreditation to the ISO/IEC 17025 Norm. It is the first company in the world to earn the highest level of accreditation for seismograph’s velocity transducer calibration. It has taken the laboratory almost 5 years to achieve the accreditation.

The laboratory is able to undertake linearity testing (calibration) of all commercially available seismographs.

Accudata GVM-1 graph of linearity

The graph relates to Accudata GVM-1 S/N:2838 manufactured in October 2014 – click on the graph for a better view

Accudata celebtrates 12 years in business

Accudata was set up by Andrew Maslin and Alan Williams in December 2001 and began trading in the first week of August 2002. The business has grown year on year and now, as we enter our 13th year, we look forward to continued growth and the addition of new products to our range.

Accudata is now one of the UK’s largest suppliers of ground vibration monitors to the civil engineering sector and we also supply noisemeters, anemometers and water leak detectors.

Our rental fleet has been considerably expanded since the launch two years ago of our Accudata GVM-1 meter, followed by the introduction of the GVM-Alert, our two-stage wireless alarm system, earlier this year.

We continue also in our role as sole UK distributor of the Nomis range of American seismographs and sell their SuperGraphs and Mini-SuperGraphs to the quarrying industry.

We are pleased to have Lesley on the board of directors as our Company Secretary and are soon to employ another pair of hands to help us in our quest to provide the highest levels of customer care, technical support and after sales service for which we have become so well known.

Accudata’s GVM-Alert System

Accudata’s new GVM-Alert is proving very popular with our rental customers.  Designed, like the Accudata GVM-1, for extreme ease of use, the GVM-Alert doesn’t really need a user manual although written instructions are included.     GVM-Alert in carrying case with GVM-1

Accudata GVM-Alert with Accudata GVM-1, a two-stage wireless alarm

The transmitter unit sits in the case alongside the GVM-1.  The receiver unit with sounder and LEDs may be used up to 30m away to warn by flashing LEDs and an audible alarm (that may be switched off by the user) if levels of ground-borne vibration exceed either of the two user set levels of Peak Particle Velocity (PPV).




Accudata’s GVM-1 Ground Vibration Monitor (Seismograph)

Now in its 12th year of trading, Accudata has risen to become a top supplier of ground vibration monitors (seismographs). The Accudata GVM-1 has been designed for extreme ease of use so that an instruction manual is unnecessary, helpful for users unfamiliar with seismographs, often on site working against the clock in adverse conditions. The Accudata GVM-1 uses the latest technology to ensure a very high degree of accuracy and has a very high specification allowing measurements of Peak Particle Velocity down to 0.03mm/s and with a resolution of 0.01mm/s.

Unlike many other seismographs, the Accudata GVM-1 is designed for measuring ground-borne vibration arising from civil engineering work and not for monitoring quarry blasts, so it does not have an air over-pressure transducer -another level of complication found on almost all other seismographs that are designed for quarry blasting, but never needed when monitoring during civil engineering works.

The Accudata GVM-1 has a single ON button. At switch on and during the 5 second initialisation, a check is made to ensure that the monitor has its tri-axial geophone sensors attached, that the SD memory card is plugged. The internal Li-Polymer batteries are also checked and the level of charge is shown on the display.

The high resolution colour touch screen displays five options:

1. Start recording, selecting this option on the touch screen begins recording.
2. Configuration, this option enables the date and time to be checked or set.
3. Status, shows the serial number, hardware and firmware versions, calibration date, battery level and number of records stored.
4. Show values, displays the levels of each event stored on the SD card.
5. Turn off.

The internal clock of the GVM-1 is extremely accurate, so the date and time are not prone to drifting as is the case with some seismographs.

When monitoring is complete, the SD card is unplugged from the GVM-1 and plugged into a computer where the records (up to 500) are automatically displayed in a dialogue box. The analysis software is supplied on a memory stick together with a single page user guide and full instructions. It is not necessary to install the software as it that can be run directly from the memory stick – useful when companies IT departments do not allow installation of third party software without testing it. The software may also be installed.

Because the Accudata GVM-1 is never directly connected to a computer, the user is spared all the connectivity issues that may be experienced with other seismographs. Also, because the analysis software runs without the need of any operating system drivers, the many and varied installation problems and the resulting frustrations so often encountered by users of software, are totally eliminated.

Accudata supplies the Aquascope-3 Water Leak Detector

Since 2010, Accudata has supplied the Aquascope-3 water leak detector for sale or hire. The Aquascope-3 is designed and manufactured in Switzerland and is well made, reliable and best of all, very easy to use. It has proved to be a great success with our clients who report back praising the instrument.

The Aquascope-3 uses a sensitive ground microphone and the user listens and searches for the noise caused by the leak. As it is often difficult to distinguish different levels of loudness, the Aquascope-3 has a numeric display (the louder the noise, the higher the number shown). This approach is a great help in locating the leak.

Rental clients include major UK manufacturers, stately homes, building contractors, Premiership Club football grounds, plumbers and drainage engineers.

Accudata supplies the Aquascope-3 in a robust carrying case with all the accessories needed, as shown in the picture.

Aquascope-3 in the carrying case




Accudata has recently added the GVM-Alert to the product range.

The GVM-Alert is a two-stage wireless alarm system for use with the Accudata GVM-1 ground vibration monitor to warn when levels of Peak Particle Velocity in mm/s exceed either of two user set thresholds.  The alarm levels are adjustable  between 0.5mm/s &100mm/s.

Alerts are provided by an audible beeper, that may switched off if not required, and a flashing amber LED if levels exceed the first user set level  and a flashing red LED if levels exceed the second user set level.

The transmitter unit is plugged directly into the GVM-1, whilst the receiver unit may be moved around as necessary so long as it is kept within the 100metre range of the transmitted signal.

Accudata GVM-Alert

The Accudata GVM-Alert Wireless Alarm System