What our experts say …
Founded more than 20 years ago by managing director David Grant, ACT Meters has become, more or less, the first port of call for testing and troubleshooting equipment used by technicians within the security industry.
Operating from a single site in Rainford, Merseyside, ACT manufactures and distributes world-wide a vast range of diagnostic tools, filters and custom built modules, of which the ACT720 is the most recent addition.
The device is actually supplied by Extech Instruments in Taiwan, then badged and supported as part of the ACT products portfolio. It carries the European CE mark for electrical conformity and comes with ACT’s usual two year warranty for all its products.
Construction and design
Most installers will be familiar with the yellow industry standard autoranging ‘3000’ meter that has been available from ACT for many years. At first glance this device is not too dissimilar – it’s the same size and layout with a central rotary function switch to provide different value measurements of voltage, resistance and current, within a removable tough rubber holster to cushion against mechanical shock.
This being a high quality multi-meter, the range of values includes measurement of capacitance, diode integrity and temperature, using the dedicated probe. The device is robust and should last for many years if treated with reasonable care.
The upper section contains the datalogging switches to set and record, in the non volatile memory, a series of readings to be examined after a determined period for analysis. The total number of sample readings that can be held in the NVM is 48000, and the sample rate of readings is adjustable in various preset frequencies – from 20 times per second up to once every 480 seconds.
We couldn’t ,in all honesty, think of a use within the security industry for such a long period between sample points. But, more usefully, there is enough memory to sample and record, for instance, a resistance reading five times per second for a period of 160 minutes.
One use that immediately springs to mind is to monitor the resistance of the relay output in a traditional inertia sensor. Other obvious uses would include suspect anti-tamper switches and hard wired ‘tube and wire frames’. Although the use of these kinds of device in newly specified installations is very much in decline, there are still plenty of them out there.
The datalogging information is immediately available using the illuminated LCD meter screen, but ACT has thoughtfully provided an RS232 output that can be used to upload the readings to a local PC running Windows. The data can then be analysed more effectively on a full sized computer screen, such as a laptop, giving a graphical display in ACT’s software.
The unit is powered by a single 9v battery, has a switchable LED back light to illuminate the display, and comes with high quality silicone-covered leads including insulated crocodile clips. There is no protective case for the 720, though one is separately available from the company.
In common with most modern meters, the 720 incorporates a battery saving cut-out if the device falls into disuse after a period, in this case, of 17 minutes. If, however, the meter is in datalogging mode over a long period of time, the unit will stay ‘on’ but fall into a low energy sleep mode in between reading samples. This enables engineers to set the meter to read samples, perhaps overnight or longer , returning subsequently to check the log for unusual activity.
It doesn’t take long to get the hang of the datalogging operation, though ploughing through the individual samples one at a time is quite tedious. If at all possible, it would be better to connect the device to a local PC and upload the data for an easier, visual analysis.
The front face selector and function switches look robust enough to last a long time, and the rubber holster adds to the quality feel of this meter. The readings were consistent every time, and though our particular device was delivered without a calibration certificate, comparison with another meter demonstrated the accuracy expected from such an upmarket diagnostic tool.
The temperature measurements were fun to use, giving rapid readings in either Centigrade or Fahrenheit.
Technical literature and support
All the meter information is available in an 18 page manual that is written, not surprisingly, in native English. For the most part, the metering operation is intuitive and of course much the same as any other quality meter.
Security technicians will be entirely familiar with the main rotary switch settings of current, voltage and resistance, though the datalogging side of things needs some experimentation and the supplied manual just about covers the procedure. In fact, an additional pdf file is available for download from the ACT web site that covers more detailed operation of specific tasks, such as how to datalog a shock sensor over a period of time, together with colour photographs and expected sample values.
Useful stuff, and ACT’s enviable professional reputation is in no small part due to the high quality of technical literature, together with an abundance of information on general fault finding and best practice for security systems installation.
As usual, anonymously, we called ACT during working hours to check some technical issues. After selecting the technical enquiry option we were put straight through to top banana, David Grant, who was happy to answer the specific questions and willing to chat further about the 720 and, indeed, similar ACT products.
