Modern replacement for 2-channel recorder with high voltage input needed - Page 1
Forum section: electronics / testgear

author: Martin72
author_rank: Super Contributor
timestamp: August 11, 2023, 07:30:13 pm
content: Hi folks,I have searched my fingers to the bone, maybe I searched with the wrong term (then you usually do not find anything clever), "last" hope are you....The following situation:For an ancient project, we used for decades a 2-channel paper recorder that recorded or wrote on paper roll for at least 8h the output voltage and ambient temperature.This device is defective and there is no more paper for it.Now we have the 21st century and are all paperless on the road, everything digital.So there should also be a corresponding new replacement for it, or...There is also, we ourselves have various recorders from hioki and yokogawa in the house.But for the project 2 channels are enough, or 4, we do not want to use an expensive hioki with its 10/20 channels for it.And now comes the special:We need a measurement input which "tolerates" 115V/400Hz.Our recorders have max 50V, the others I have found on the net, also have only max 50V in the input.So the question is, is there a recorder that can handle a higher AC voltage and has a temperature input?I would be very grateful for any advice.

author: tautech
author_rank: Super Contributor
timestamp: August 11, 2023, 08:05:36 pm
content: SDS1104X-E in Logging mode.https://int.siglent.com/u_file/document/Data%20Logger%20of%20SDS%20Application%20Notes_EN01A.pdf

author: Martin72
author_rank: Super Contributor
timestamp: August 11, 2023, 08:25:21 pm
content: Very interesting !But unfortunately no temperature...Hmm...of course you could use a separate temperature logger and include the csv files later together in a table...OK, that would be a possibility, if there is really no recorder with high input voltage.

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 11, 2023, 09:43:56 pm
content: You could connect a temperature sensor, that outputs a DC voltage, to the second channel on the SDS1104X-E. Depends on how accurate this needs to be.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 11, 2023, 10:52:12 pm
content: Any reason you can't just put a resistive divider on the in high voltage signals to bring them into the operating range of standard commercial data loggers? Also, if you were actually recording the raw 400 Hz waveform in any kind of viewable format you must have been going through kilometers of paper. Roughly forty centimeters/second would be about the slowest you could run it. I remember filling lab floors many centimeters deep doing this kind of stuff at somewhat higher bandwidths fifty years ago.If you are more interested in voltage droops and other similar phenomena that vary with similar bandwidth to the temperature signal you could rectify and filter the signal with appropriate scaling to match any number of commercial recorders (data loggers). Or for a cheap alternative an Arduino or similar would do the job.

author: nctnico
author_rank: Super Contributor
timestamp: August 11, 2023, 11:17:43 pm
content: Perhaps a logging multimeter is an idea to pursue. Google shows quite a few options.

author: tautech
author_rank: Super Contributor
timestamp: August 11, 2023, 11:43:48 pm
content: Quote from: Kim Christensen on August 11, 2023, 09:43:56 pmYup, and with enough swing set a Mask to it to raise an alarm if needed.Martin AFAIK already has SDS1104X-E and if required could add a LAN or WiFi connection and monitor results remotely via the webserver.Doing this he could also download captures and set for Single shots that exceed preset limits.Also if the NTP server was set up correctly timestamps on events can be obtained.

author: nctnico
author_rank: Super Contributor
timestamp: August 12, 2023, 12:29:31 am
content: 8 bit is not going to be good enough for a temperature sensor. You'd need at least 12 bit for that if you want a reasonable reading. A range of 30 degrees with 0.1 degree resolutation is already way outside the realm of any 8 bit acquisition system.I also have a feeling that any form of computerised automation is also out and Martin72 is looking for a standalone unit that can be setup and do the job by itself.

author: zepto
author_rank: Regular Contributor
timestamp: August 12, 2023, 01:53:12 am
content: Look at Hioki MR8880, it has 4x 600v tolerant inputs at least.There are DC amplifiers that can amplify/attenuate to some kilohertz, 400Hz pretty easy. AL1301A is an example.Resistive divider like someone mentioned is cheap solution, 10x oscope probe might even work for some recorders. I am sure they make HV probes for recorders too.

author: Martin72
author_rank: Super Contributor
timestamp: August 12, 2023, 06:34:57 pm
content: Hi,Quotehttps://www.hioki.com/global/products/data-acquisition/daq-maintenance/id_5776Damn....Why not with a temperature input...We have two from this here:https://www.hioki.com/euro-en/products/multichannel-data-loggers/multichannel/id_5799You could take both (MR and LR)and then merge the data.But then a 10-channel logger would be blocked with only one channel.Let's see, I'll think about it a bit more, also regarding a possible voltage divider.And whether I can change the scaling at hioki lr accordingly, that he does not display 11.5V but 115V.

author: egonotto
author_rank: Super Contributor
timestamp: August 13, 2023, 03:48:16 am
content: Hello,Unfortunately, I do not understand the requirements sufficiently.At what frequency should the sample be scanned? Should the RMS value of the input voltage be measured?So it's not clear to me if my hint is useful, but if not, it's not a bad thing.Perhaps a device from the Analog Discovery Pro 3000 series will suffice. These have 14 bits with a maximum of 125 MSamples/s. However, there are only the input ranges +-1 V and +-25V with possible offset. There is a two-channel and a four-channel device. There is a logger mode. The devices can be operated via USB or LAN, but have a standalone operation (Linux)Digilent has a very good forum when questions need to be clarified. The four-channel devices cost about € 1200 excluding VAT.I almost sound like a sales person, but I'm not. However, I do own a few Analog Discoveries.The WaveForms software can be downloaded for free and tried out in demo mode.You can use normal probes, so a range of +-250 V is easily possible. The temperature could be detected with an external sensor if you use the four-channel device.Best Regardsegonotto

author: BILLPOD
author_rank: Frequent Contributor
timestamp: August 13, 2023, 02:03:56 pm
content: EEVblog 121GW with a thermocouple.Just hit the 'MEM" button.

author: simba15
author_rank: Regular Contributor
timestamp: August 14, 2023, 01:34:16 pm
content: I have done lots of environmental testing with Hioki GL840, with over 40ch of data logging. ( temp or voltage or current)Good unit, but software and menus are a bit outdated when compared to modern scopes, but functionally works great.

author: Martin72
author_rank: Super Contributor
timestamp: August 15, 2023, 09:13:15 pm
content: Hi,I'm going to feed the Hioki a 400Hz voltage the next few days at work, less than 115V of course, to see if it even measures/displays correctly.If that works, I will calculate a 1:10 voltage divider.We have 0.2% resistors in stock, so that the accuracy can be sufficiently taken into account.I will then report with results and thank you already now all who had participated with ideas and suggestions.Nevertheless, I find it amazing that there is no direct successor to the old paper recorders, which can measure high voltages and temperature (-sensors) simultaneously.

author: tautech
author_rank: Super Contributor
timestamp: August 15, 2023, 09:23:46 pm
content: Quote from: Martin72 on August 15, 2023, 09:13:15 pmSDM3000 in Dual measure mode ?

author: Martin72
author_rank: Super Contributor
timestamp: August 15, 2023, 09:27:15 pm
content: Can it record the values over at least 8..10 hours Rob ?

author: tautech
author_rank: Super Contributor
timestamp: August 15, 2023, 09:55:10 pm
content: Quote from: Martin72 on August 15, 2023, 09:27:15 pmNever tried.However you have these and depends on the accuracy you need as with the lower reading rates the memory will take longer to fill.1 Gb NAND flash size, Mass storage configuration files and data files.Study the user manual and do some tests yourself.

author: Martin72
author_rank: Super Contributor
timestamp: August 15, 2023, 10:20:38 pm
content: QuoteI will then tell you if and how it works.

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 15, 2023, 10:23:12 pm
content: Another option would be to run software like LabView, MyOpenLab, etc, on a PC and connect via USB, serial, LAN, GPIB, etc to the required instruments, DAQ, etc. Then you can have all kinds of fancy graphs, storage, and analysis.

author: Martin72
author_rank: Super Contributor
timestamp: August 15, 2023, 10:39:08 pm
content: When i just skimmed the manual of the sdm 3045x, this would be the only possibility, because the multimeter can not directly store something continuously.There would only be the possibility to address it externally and to query and store data via polling.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 16, 2023, 12:12:15 am
content: Quote from: Martin72 on August 15, 2023, 09:13:15 pmI don't find it amazing. These paper chart recorders started in the vacuum tube era, and their demise came when A to D converters became small and cheap. Their replacements didn't have to deal primarily with high voltages, instead instrumentation had moved down to much lower voltages and currents. The market for high voltage recording had shrunk.In addition, signal conditioning was frequently a requirement for all of these systems, from the paper recorder era on, so expecting a customer to provide needed voltage dividers, clamps, rectifiers and filters as required was not a shock to the market. If you are willing to accept this requirement for signal conditioning there are really a lot of devices on the market. From just one vendor for example:Module that interfaces to computer for data storage and displayhttps://www.omega.com/en-us/data-acquisition/data-acquisition-modules/p/OMB-DAQ-2408-SeriesFull data logger. Does all data collection and storage. Will require a computer to display/analyze the data.https://www.omega.com/en-us/data-acquisition/data-loggers/multichannel-programmable-and-universal-input-data-loggers/p/OM-CP-OCTPRO-Logger

author: Caliaxy
author_rank: Frequent Contributor
timestamp: August 16, 2023, 03:49:34 am
content: Fluke t3000fc (about $220 in US) can record about 65000 datapoints in its internal memory. I used one recently to monitor the temperature in a freezer (for about 22 days, continuously, one datapoint every 30 sec). Worked flawlessly. The batteries (2 AA) last about a month. Fluke sells specialized units for different measurements (each unit can only measure one thing - DCV, ACV, DCA etc.; to monitor two voltages and a temperature, you need three units). The hardware quality is superb. Each data point is time stamped, so the traces can be correlated.

author: Domitronic
author_rank: Regular Contributor
timestamp: August 16, 2023, 10:05:33 am
content: How about the Keithley DMM6500 with scanner card? AFAIK it can store up to 7M measuring points on internal memory. Not sure if it is able to write data directly to external USB drive while measuring or only after recording has stopped. Might be worth to check the datasheet.

author: HighVoltage
author_rank: Super Contributor
timestamp: August 16, 2023, 10:17:11 am
content: Why not a Keysight Data Acquisition unit 34970A or 34972AThis is especially designed for the application you have

author: Domitronic
author_rank: Regular Contributor
timestamp: August 16, 2023, 10:52:22 am
content: Quote from: HighVoltage on August 16, 2023, 10:17:11 amI agree. Seems to be the better choice compared to multimeters but also more expensive. The ones you mentioned seem to be discontinued. But there is the DAQ970A / DAQ973A now. And from Keithley the DAQ6510.

author: ledtester
author_rank: Super Contributor
timestamp: August 16, 2023, 11:10:44 am
content: What sampling rate do you need?

author: Martin72
author_rank: Super Contributor
timestamp: August 16, 2023, 07:09:48 pm
content: Hi,It's hard to say when it was completely analog before.I had looked at the device today for the first time, looks funny with the paper roll inside, with the millimeter imprint.But the colleague who told me that we need something new, he can tell me tomorrow times, where he wants to have the measurement voltage connected to the recorder.I could not see anything earlier, except temperature inputs ..

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 16, 2023, 07:45:15 pm
content: Quote from: Martin72 on August 16, 2023, 07:09:48 pmWell, the pen line thickness and the max paper feed rate, should give you a good idea about a ballpark "sample" rate.

author: Martin72
author_rank: Super Contributor
timestamp: August 16, 2023, 07:55:50 pm
content: Yepp, that's why tomorrow I'll have the protocols given to me where they had pasted the paper sections.

author: switchabl
author_rank: Frequent Contributor
timestamp: August 16, 2023, 08:51:41 pm
content: Quote from: Domitronic on August 16, 2023, 10:52:22 amI think a DMM6500 with a 2001-TCSCAN card should be enough if all you need is a few thermocouple and voltage channels (up to 125 Vrms). IIRC the DAQ6510 just has more cards available (with higher channel count/special features) and you can install two of those at the same time.EDIT: The pricing on the DAQ6510 + 7700 bundle seems to be pretty similar though. So still worth a look if you don't have a DMM6500 already.

author: ledtester
author_rank: Super Contributor
timestamp: August 16, 2023, 10:18:53 pm
content: Quote from: Martin72 on August 16, 2023, 07:09:48 pmI just tested using SCPI with my Fluke 8845A and with simple programming I can get 2 samples per second through SCPI polling. (I realize this seems awfully slow but 1) I'm not an expert yet at utilizing the meter through SCPI and 2) I'm intentionally not placing the measurements into the measurement buffer because then you'll be limited by the size of that memory.)Anyway, if that's fast enough for you then polling should work for you. You might even be able to use the "program that can log from many multimeters" and avoid having to do any programming:https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/

author: ledtester
author_rank: Super Contributor
timestamp: August 17, 2023, 02:03:08 pm
content: Quote from: ledtester on August 16, 2023, 10:18:53 pmAn update... I figured out how to stream readings indefinitely from the 8845... you use the READ? directive. The Fluke user manual has this to say about measurement rates - the Ethernet interface is capable of transferring 900+ measurements/sec.

author: Martin72
author_rank: Super Contributor
timestamp: August 17, 2023, 09:09:49 pm
content: I´ve looked in a protocol today with a measurement section copied in there from the recorder, it´s hard to read...The outputvoltage is plotted as a line, so it´s measured in rms.Paper stroke is 20mm/h, so the length after 8 hours is 160mm.If I have the time tomorrow, I would test the hioki if it measure( and displaying) the voltage in rms.