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"I am not often taken by surprise, Whenever a company submits their product for my thorough bashing, it is usually delivered in a relatively sturdy cardboard box with at least a few layers of 'bubble wrap' if not protected by a good few centimetres of foam chips! This is done to ensure the instrument has at least a fighting chance when I get my mitts on it! Not so in this instance. Acksen posted it in an extremely well thought out reusable case. There is a window where any posting document can be inserted with the customer's name and address. On the inside is another where one can store the return advice slip, for example a card with 'freepost' details to ensure it gets back to the rightful owner. The inside window, in this case, held the software. But software is only good to one when there is some data to download. The unit was duly plugged in and, as was indicated in the brief instruction sheet that accompanied the unit, the red LED started flashing showing that the unit was in Record mode. This really does give a "warm fuzzy" feeling that both the unit and the socket the unit is plugged into is working. The original software arrived on two 3½" diskettes. I need to be honest, this is usually when I start feeling that there is going to be little to offer. Somehow we are starting to be conditioned into believing that anything worthwhile will be on nothing less than a CD. Huh! In this case, this is very wrong thinking! The two diskettes held a program that is not just the graphical interface for the recorded data, but also a logger management tool complete with database. It allows you to keep track of the loggers, where they have been sent, when they are due back, as well as a means to print address slips for both despatching to the client and for the client to post the logger back to you. As for the graphical data, there is not just the usual "min, max, and average" graph, but comes complete with adjustable markers and tolerances indicators (as well as fixed accepted tolerances based on EN50160 including all the flavours of this spec!) and a few statistical indicators too, the most handy one being "Overall Average". The "Statistics" tab reveals a simply gorgeous histogram together with all the markers mentioned above. Voltage complaints are the primary reason such recorders are used, so this is the most important style of graph one could give a customer. Nothing more than a quick glance is needed to indisputably show my local electricity supplier is deliberately shoving the voltage up! The histogram data is available for export via the "Duration" tab.
Some more technical things. The voltage is "true RMS" down to one cycle (sampled at 32 samples per cycle). This means it is a genuine maximum and minimum being recorded, not some averaged value after an analogue AC to RMS converter (as is done on some similar recorders in the same price range). Although there is no direct transient capture, with a true 32 samples per cycle the recorder will tend to capture any violent disturbance of 500µs and longer (it is likely to fall within the capture window of one of the sample takes). Recording intervals are from 1 second to 15 minutes (on the 64kB version that’s a range of 1½ hours to 112 days!). Resolution is the key to solving problems, but many recorders fail when configured to comply with the abominable teaching saying recordings must be done for one week! At 7 days the Electrocorder has a fault resolution of a mere 60 seconds.
Communications on the plug-in versions is via a special RS232 cable (IP65 model is standard 9-pin), and has no problem communicating via an economical USB to RS232 converter. The comms port is galvanically isolated to well beyond a few kilovolts using opto-couplers, and had no problem communicating over a 20 metre com extension cable. This is a standard test of mine as such isolation techniques tend to fail when using long cables yet many instances exist where a recorder may have to remain powered while the data is downloaded but is too far from the PC for the standard cable (there is a note saying they advise against downloading while powered, but this is simply for safety as no-one can control contamination or insects that might be shorting out the back of the PC board). If you're a large organisation, and have a number of "data gatherers", then the advanced feature "Email The Downloaded Data" is a pretty neat one. It simplifies the operation to downloading the data, email it to one of 3 pre-set email addresses (all the "attaching" done automatically), and continue on to the next voltage complaint. Another endearing feature of the recorder is the ability for the user to perform their own calibration (you need to register the software to unlock this feature). I know a volt should be a volt, but it is nice to be able to calibrate all your PQ kit from the same source thus making comparative measurements, well, comparative! With regulation standards now breathing down the necks of service providers, the advanced feature of the "calibration monitor" may prove attractive to large organisations as it assists in keeping track of when recorders are due for testing and unlikely calibration. When I display my kit at talks I deliver on Power Quality, this recorder attracts a lot of attention from attendees. Every requirement they pose seems to be fulfilled with this little beast. This proves the value-for-money ratio of the whole kit is well above par! With other recorders I have tested I've always felt "there's something left out of this". Not so with the Electrocorder. Instrument Index (simple recorders) >>
© 21.06.03 / 04.10.04 |
MEASUREMENT TECHNIQUES:
Another part I really liked was the battery condition monitor, and it's not just a little flag that says it's time to change the battery! How many times I have seen loggers leave for a customer and fail because the battery was on its last legs, but still had enough to pass the despatch test! As you can also see, the battery lasts a long, long time!