Anyone has used Valhalla Scientific 80s Multimeters? - Page 1
Forum section: electronics / general

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: July 22, 2017, 02:48:15 pm
content: Hey everyone,a friend of mine offered me a Valhalla Scientific "vintage" Multimeter with integrated counter. I have to admit that I have never heard of that brand before and certainly can't find much about this meter. It is a Model 4440, in perfect working condition with some signs of use. From the information found in the datasheet it seems to have been a high class device back then but from a modern point of view... well, take a look for yourself.http://www.valhallascientific.com/manuals/4440_Manual.pdfHe offered me this thing for 65€. Since I really like the name of the company (yes, I admit, I love nordic mythology) and I tend to collect all sort of vintage test equipment I am tempted to buy it, but the price seems a bit high, compared with the specs. Couldn't find any comparisons online as they seem to be sold not that often.What do you think about the brand in general as well as the model he offered me and the price?

author: MosherIV
author_rank: Super Contributor
timestamp: July 22, 2017, 03:18:32 pm
content: HiI do not know about the DMM that you mentioned. I know that Valhalla Scientific made really nice calibrators :http://www.ebay.co.uk/itm/VALHALLA-SCIENTIFIC-2703-Programmable-AC-Voltage-Stand-S-N-27323-/302265168718?epid=1725119144&hash=item466068734e:g:JC4AAOSwuLZY2Rpmhttp://www.ebay.co.uk/itm/VALHALLA-MODEL-2701C-PROGRAMMABLE-PRECISION-DC-VOLTAGE-CURRENT-STANDARD-D2-/192240196202?hash=item2cc2689a6a:g:8uUAAOSwRXRZXq28

author: CalMachine
author_rank: Frequent Contributor
timestamp: July 22, 2017, 03:21:46 pm
content: I've not worked with this particular model before, but Valhalla Scientific did make some pretty decent equipment. I am more familiar with their DC standards and power meters.

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: July 22, 2017, 04:37:57 pm
content: Thanks for your replies. I noticed already their DC calibrators and also found a nice thread about one here at the forums. Sadly, those are far out of reach for me, pricewise.So the brand seems to be rather decent I guess?Did anyone take a look at the datasheet? I am really unsure if the price is "okay", since you can get an Uni-T UT61E for around the same price, has the same functions and resolution, but worse (around half) in term of accuracy.On the other hand, a tabletop multimeter with that accuracy and functions will cost you nowadays around 200€ or more.

author: Muxr
author_rank: Super Contributor
timestamp: July 22, 2017, 05:17:35 pm
content: I glanced at it, it's an older DMM. Manual ranging would be a show stopper for me. Also kind of the biggest thing about bench DMMs at least for me is being able to control them programmatically, and I didn't notice any interface on it.If you're looking for a cheap bench DMM, I would checkout HP 3478A. They can be found for under $100 and are great meters for the money.

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: July 22, 2017, 05:56:11 pm
content: Quote from: Muxr on July 22, 2017, 05:17:35 pmThey don't have any interface as far as I noticed.QuoteI have not really a need for a new meter (since I already have many), I just love collecting and tinkering with old stuff

author: MosherIV
author_rank: Super Contributor
timestamp: July 22, 2017, 06:05:36 pm
content: QuoteNo, the Valhalla beats the UT61E in accuracy terms by a long shot.The DCV accuracy of the Valhalla is about 10 times better.QuoteMaybe in USA, here in Europe they go for over £100I collect DMMs as well. Have you got Solartron/Schlumberger?The 7150 is quite well thought of (for a 5.5 digit, the 6.5 mode is actually averaged from the 5.5)I have also got the true 6.5 digit Solartron 7060

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: July 22, 2017, 06:22:49 pm
content: I must admit that I just had a short look at the Datasheet and accidentaly looked at the chart for the UT61E's DCV part, which is .1% vs the .05% on the Valhalla, the other parts are way worse.Sadly, I don't own any Schlumberger gear right now, I've been looking for something from them but it was most of the time over the budget.

author: MK
author_rank: Regular Contributor
timestamp: July 23, 2017, 10:46:10 am
content: I have seen the 7150 go quite cheaply at times in Europe and the UK, it does do quite well.

author: mimmus78
author_rank: Unknown
timestamp: July 24, 2017, 10:38:30 am
content: 7150 has 10M ohm input also at 10V ... so 6.5 digits seems quite optimistic.

author: Edwin G. Pettis
author_rank: Frequent Contributor
timestamp: July 24, 2017, 07:44:06 pm
content: Valhalla made good basic instruments, not necessarily state-of-the-art but they worked well and had good reliability, during much of the '80s we made the precision resistors that went into Valhalla. I have one of their 2703C loaded with our resistors.The 10Meg input load resistance was a standardized load for DVMs, mainly of higher performance units of the day, most of the hand-held analog VOMs were passive and mainly depended on the sensitivity of the meter movement, you couldn't use a high input value divider with meters that were in the 10K to 50K /volt sensitivity. When digital DVMs started coming out, with active circuitry, the sensitivity was much higher allowing for a 10Meg input, later when protection circuits were up to it, input resistance increased to nearly an open circuit value, >100Meg on the low voltage ranges. Not all DVMs take advantage of the possible higher input resistance, 10Meg is still an often used standard.Back in the earlier electronic age, before ~1970, it was not unusual to see voltage tolerances on many schematics of 10% or 20% using a VOM (the relatively low input resistances was taken into consideration in the measurements). Higher accuracy instruments were quite expensive and relegated to labs, industrial and military.Resolution is basically a function of the circuitry and the designer's wish to display more digits, whether or not it actually increased accuracy, this game of resolution is still played today, rarely is the LSD of any consequence or accuracy, various factors tends to negate any real functionality of the last digit or even the last two depending on the design. Accuracy is almost always limited to the PPM digit of the reading, i.e. about 6 digits at best, few DVMs (3458A) are actually accurate in the PPM range and are usually limited to >10 PPM accuracy. Note that the LSD can impart some useful information in a limited manner, such as direction of change (analog meters were particularly good for this). A 3456A at 6.5 digits can actually have an accurate LSD after calibration, but within a relatively short time, the accuracy slowly slips up to the next higher digit making the LSD almost of no use as far as accuracy goes.A great example of overuse of resolution is the case of a counter which uses the power line frequency as the gate reference. While the long term drift of the power line is rather low, the short interval frequency deviation can be significant, therefore a line frequency based counter is considered to have a short term accuracy of 0.1% at best, while the counter may display 6 digits of resolution, only those within 0.1% are of any use essentially making three of the display digits of no use, resolution is a great marketing tool but in practice, not so much.