Bryman BM257 Datalogging - Page 1
Forum section: electronics / general

author: Synthetase
author_rank: Regular Contributor
timestamp: September 07, 2016, 02:43:24 am
content: First up, what I want to measure:The AC line voltage at our house is too high, but it's not always too high. It hovers around 250V, but does go above that. Generally on a weekday, it's okay, but on weekends, it does shoot up quite a bit. We have some problems with some appliances because of this - and when it's over 256V, it's technically out of spec and our supplier needs to fix it. However, I've had problems convincing them that it's happening. I called them once when it was over 256V and they sent a couple of technicians over almost a week later, measured the voltage and it was about 247V, so they told me I was full of crap.What I want to do is measure the mains voltage over a long period of time (at least a week) so I can see what's happening and so I have some hard data to show my supplier. I have a Brymen BM257 meter and I was thinking about getting the PC data logging cable accessory for it so I could do this. Before I do that though, I thought I'd ask if anyone here has experience using this software.How long/how many capture events can you capture before it falls over? Ideally, I'd like to tell it to take a reading every minute or so and leave it sitting there for a week. Is this possible, or will I have to manually stop, save, export and restart it as the buffer becomes full?Has anyone else in Melbourne (or elsewhere in Oz) had high mains problems and how did you resolve the issue?Thanks in advance.

author: zlymex
author_rank: Frequent Contributor
timestamp: September 07, 2016, 03:28:26 am
content: I once being asked to log the AC voltage in my office for 1 month and a data logger of battery powered, no lager than a cigarette case was given to me. I recalled that the sample interval is 1 minute.I also have the same problem in my house of over voltage. The nominal voltage is 220VAC here but often measures at around 240VAC. Possible reasons include the off-balanced load of three-phase 380VAC, or the power company deliberately adjust the voltage to high limit in the hope to collect more fee.

author: mtdoc
author_rank: Super Contributor
timestamp: September 07, 2016, 03:58:21 am
content: Quote from: Synthetase on September 07, 2016, 02:43:24 amI have the meter and data cable. I've only played with the software a bit and never tried to do any long term data logging.The software can be downloadedhereFWIW the included read me file says this: "Virtually no software limitations on the maximum number of items for long-term data logging as long as your PC system can afford. But still, longer sampling interval (slower sampling rate) selection is recommended for long-term data logging to reduce system burden and file size use"So it sounds like the length of recording is only limited by the sampling interval and disk space on your computer.

author: Synthetase
author_rank: Regular Contributor
timestamp: September 07, 2016, 05:12:57 am
content: Cool. So it looks like it should be able to do what I want it to. Thanks.

author: MosherIV
author_rank: Super Contributor
timestamp: September 07, 2016, 08:58:28 am
content: HiDo not forget that the meter need to be put into a mode where it does not auto power off.The battery life might be an issue if you are logging for more than 1 week continuously.

author: Synthetase
author_rank: Regular Contributor
timestamp: September 07, 2016, 12:14:17 pm
content: Yeah, I looked into it and I think you hold down one of the function buttons (hold or select, can't remember which one) when you turn it on to put it into the correct mode.To eliminate the battery life issue, I was going to run it from a bench top power supply set to 3V.