USA Cal Club: Round 2

[rhb]

I am in possession of the USA Cal Club kit!

I won't have it long, my best multimeters are only 5.5 digits but it affords me the opportunity to test the calibration at all, so for that I'm very appreciative.

I can't imagine that the virus crisis is doing us any good...however the club is still going strong! Currently the kit is with technogeeky.

This is quite disturbing.    Since the 10 February post technogeeky has posted once on 11 April.  Based on his 10 February post he should have sent it back long before then.

I sent a PM to vindoline asking if he had heard anything from technogeeky before I looked into technogeeky's posting history.   Hopefully he will respond here.

If someone misaddresses the package when returning to vindoline it can be lost forever.  And packages do disappear in transit with all carriers even when correctly addressed.

Hopefully the kit will turn up, but I'd like to suggest some procedural changes:

Preprinted shipping labels.  Use the USPS service to print a return label and an outbound label and email the outbound label to the person getting the kit for verification before shipping.  Put the return label in the kit.  I think that will assign a tracking number for each leg so it can be tracked even if mischance befalls the person getting the kit.

Place a label on the kit describing it and where it should be sent in the event the person who has it passes away.  Covid-19 makes that a much greater risk than before.  At present no one dealing with the estate of the person who has the kit would have any clue what to do with it.

Require insurance when shipping.

It might be a good idea to require a security deposit via PayPal to be refunded upon return of the kit.  I don't think anyone would sign up to the list to steal the kit, but it's possible.  There could also be a penalty factor for delays in turn around not justified by work presented as a means to deter sloth.

Reg

[technogeeky]

I am in possession of the USA Cal Club kit!

I won't have it long, my best multimeters are only 5.5 digits but it affords me the opportunity to test the calibration at all, so for that I'm very appreciative.

I can't imagine that the virus crisis is doing us any good...however the club is still going strong! Currently the kit is with technogeeky.

This is quite disturbing.    Since the 10 February post technogeeky has posted once on 11 April.  Based on his 10 February post he should have sent it back long before then.

I sent a PM to vindoline asking if he had heard anything from technogeeky before I looked into technogeeky's posting history.   Hopefully he will respond here.

If someone misaddresses the package when returning to vindoline it can be lost forever.  And packages do disappear in transit with all carriers even when correctly addressed.

Hopefully the kit will turn up, but I'd like to suggest some procedural changes:

Preprinted shipping labels.  Use the USPS service to print a return label and an outbound label and email the outbound label to the person getting the kit for verification before shipping.  Put the return label in the kit.  I think that will assign a tracking number for each leg so it can be tracked even if mischance befalls the person getting the kit.

Place a label on the kit describing it and where it should be sent in the event the person who has it passes away.  Covid-19 makes that a much greater risk than before.  At present no one dealing with the estate of the person who has the kit would have any clue what to do with it.

Require insurance when shipping.

It might be a good idea to require a security deposit via PayPal to be refunded upon return of the kit.  I don't think anyone would sign up to the list to steal the kit, but it's possible.  There could also be a penalty factor for delays in turn around not justified by work presented as a means to deter sloth.

Reg

Hello folks;

I didn't use the kit at all for the first two weeks I had it due to work constraints; I used it to calibrate (or rather check the calibration) on a few meters, used the resistors to check calibration too. Unfortunately my meters are only 5.5 digits so I mostly just saw a completely stable reading.

On March 31, I replied to a PM saying how it was unfortunate this COVID craziness happened during this; I suggested we wait 5 days on either side of shipping (after boxing but before shipping; after receiving but before use) for safety reasons. I said I would send the device out if I was given an address and was told to "sit tight".

Unfortunately all of this distress was caused by me talking via PM and not in the public thread. Sorry about that.

Please let me know where to ship the device and I'll get it in the post this weekend.

[bitseeker]

technogeeky! Glad to see you're alright. Thanks for the update. Hope vindoline is around to get the address to you. I thought he included a sheet with it printed on.

[SirAlucard]

Quick question, are there any of those GPIB kits left? I need one. Or know a good place for one?

[rhb]

Here's the Uno version I made using IDC connectors.  All from ebay.  The case was around $9 for 10.

Soldering the wires was a pain which is why I asked artag to design the Uno shield version.

https://oshpark.com/profiles/artag

Have Fun!
Reg

[technogeeky]

technogeeky! Glad to see you're alright. Thanks for the update. Hope vindoline is around to get the address to you. I thought he included a sheet with it printed on.

Nope, the box included only a printed copy of my own address! I will send it out once I have a place to send it to. Hopefully it won't be long!

[vindoline]

technogeeky! Glad to see you're alright. Thanks for the update. Hope vindoline is around to get the address to you. I thought he included a sheet with it printed on.

Nope, the box included only a printed copy of my own address! I will send it out once I have a place to send it to. Hopefully it won't be long!

PM sent

[technogeeky]

The cal kit is on its way to vindoline. Thanks a bunch! I checked the calibration on almost 40 year old multimeters and they are only 1 to 2 counts out on the ranges I could check. Pretty amazing!

[VNUTDENYER]

In relation to " ATmega 328-based USB-to-GPIB adapter" in kit, any links or advice on SW for logging Arduino temp and DMM data?  Assume still best in CSV format for crunching.  Thanks.

[rhb]

 What OS are you using?  What meter?

I wrote Unix scripts to do it using as pair of 34401As.  Don't even recall which system I used, so a bit of a chore to find it.

It's just sending a series of strings to a serial port and logging the replies.  Pluse changing the device address.

Reg

[bitseeker]

In relation to " ATmega 328-based USB-to-GPIB adapter" in kit, any links or advice on SW for logging Arduino temp and DMM data?  Assume still best in CSV format for crunching.  Thanks.

If you haven't yet seen it, check out the cal club's getting started guide. It includes links to the AR488 project and the manual, which has info on installation, drivers, client software, usage, etc.

https://www.eevblog.com/forum/metrology/usa-cal-club-getting-started-user-guide/

[VNUTDENYER]

Just the DMMs and DC sources in sig. Figured on WIN7pro but could us VB or Linux.  Is AR488 what is in kit?   I need to build up AR488 or similar and get everything working before kit arrival (guessing Sept).

[vindoline]

Is AR488 what is in kit?   I need to build up AR488 or similar and get everything working before kit arrival (guessing Sept).

Hi, there is a GPIB to USB adapter in the CalClub kit that is running the AR488 firmware. For a single DMM you should be able to just plug it into the GPIB port in the back. No GPIB cables are included for daisy chaining a series of instruments. On your end you will need a PC with software to control and read the data from the AR488. I think most people use a Python script to do the data logging. I have a dedicated raspberry pi that I use for this.

[VNUTDENYER]

Thank you rhb, bitseeker, and vindoline for helpful info.  I used the long name for GPIB adapter in kit before rereading kit contents.  Just trying to figure cycle time so can decide whether to function test what I have or get more (looking at Fluke 883A tomorrow - powers up.  Later.

[bitseeker]

Seems the general consensus is that if you're doing interesting things with the kit and updating here, a little extra time to be able to accomplish those things is OK. If you're unsure, feel free to post a prioritized list of tasks and rough timeline for group input. We're a pretty laid-back bunch, which helps keep the club resilient.

[SirAlucard]

Alrighty! Giving an update to let everyone know the kit has arrived safely, I don't have much to test, so it won't likely be with me for long. As I'm mostly looking to just calibrate what I have and sent it along.

EDIT: Quick note, I noticed the arduino with the temp sensor has a resistor that snapped off? I'm assuming this isn't suppose to be the case. Please correct if I'm wrong, tho I wouldn't see why lol.

Then again it does looks like it's this way on the getting started page, I must have missed why this was.

[bitseeker]

Oh, wow. Can you tell what that resistor might be for? The LED?

[SirAlucard]

Oh, wow. Can you tell what that resistor might be for? The LED?

Yea it's just connected to that LED that's right next to it. Doesn't seem to be used tho.

[SirAlucard]

Quick update, I won't be shipping the kit back quite yet, picked up a 3478A for under $100 from fleabay. So once it shows up I'll actually have something with some decent resolution to check with and share. Granted it's in any sort of calibration. Slight cosmetic damage, but otherwise looks alright. So will look forward to seeing what kind of condition it's in.

[SirAlucard]

Alright, so the 3478A is in my hands, and here come the first few numbers! Feel free to give input if you think they aren't accurate enough. Cause personally I have a problem with wanting things to be exact.

First up resistance tests.

HP 3478A
1k Measurements
2-Wire: .99975 kOhms

4-Wire: 0.99951 kOhms


10k Measurements
2-Wire: 9.9951 kOhms

4-Wire: 9.9949 kOhms


Fluke 8012A
1k Measurements
1.000 kOhms*

10k Measurements
9.99 kOhms*

AMProbe AM-520
1k Measurements
1.000 kOhms*
10k Measurements
10.01 kOhms*

I'm going to start running the 7.0456 voltage reference and will report back my findings. So far I think I got a good deal.

*Additional Photos on Server

[SilverSolder]

Looking good! 

[SirAlucard]

Alright PX Reference numbers are in! After 12+ hours of measuring on the 3478A, again I think the numbers look really good. Tho I'm biased cause I don't want to think I got a lemon. You guys tell me! This is with Auto Zero turned off. It's been a little while, but it seems the meter has settled, and with Auto-Zero turned on it sits at 7.0459

First off the Temp/RH of my office in which I was doing the testing. It's not the most stable environment, nor the coolest. However at night when I left the office it did cool down to about 25c



Then the difference over the measured reference of 7.0456. Mine averaged out to be 7.0462 which makes it only out by .0006, I assume that's good enough to keep?

[SirAlucard]

What is the rate at which the arduino reports the temperature? It's not quite every second, and it's not every two seconds. Wondering if we can add a rtc to the arduino and have it report back the current time, as well as have it trigger every second. Unless there is a better way to log readings from an HP3478A and an Arduino at the same time into the same file. I'm just currently using HP 3478A Control to log my readings, and putty to log readings from the Arduino. I don't get the same samples, so it doesn't really tell you what the current temperature was when the reading was taken, just the general temperature of the room over time, as much as I try to keep them logging in the same amount of time.



Also with help from TiN I've got the FX Up and running. Short story I don't have a bi-polar linear PSU. So with the help of a battery I got it running, and it looks really good. A tad high for my liking, but I have an obsession with things being exact and perfect. I'm getting anywhere between 10.0000 to 10.0010. Is it recommended to take readings with Auto Zero on or off? I'm guessing off since the readings would be faster.

[SirAlucard]

Posting to let everyone know the Cal Kit is on it's way back. I've uploaded all my logs of what my 3478a was giving. Definitely needs to be calibrated to be a bit more accurate. Was able to calibrate at least the 30v range using the FX as a reference, as well as the 1k and 10k Ohm ranges. Which is perfectly fine for me. As those are my most used ranges anyways. Eventually I'll get the whole thing calibrated. For now close enough is good enough for my use case.

[SirAlucard]

So after all that, I ended up getting the part I needed to make my own GPIB connector. Personally I like things really tight and tidy, so this is for the person that complained about all the wires. Works perfectly!