Old Surveying Supply Catalogs - Invar Tapes

I'll see what I can find and send you some scans. Shoot me an email letting me know what file format you prefer and how mani dpi's you need.

Dave

ingram@cfw.com

Actually ...

I just took a quick look through a dozen or so catalogs and didn't see any Invar tapes listed. K&E did have a "Lo-var" tape listed in a catalog from about 1960, but that's it. A couple of text books from the 60's / 70's describe them and the use and Geodetic Surveying by Ingram describes the Coast Survey's first use & experimentation with them. I'll keep looking. If there's any research I can help with, let me know.

I have a K&E Lo-Var tape on a K&E wooden reel that I could take a picture of, but it wouldn't be much to see.

I believe "Lo-var" was similar to Invar, but less expensive to make. Probably a shortened name for "Low Variance". It didn't have the same thermal expansion, but it was better than using a straight steel tape. There were probably some trademark problems with making this type of alloy. It was first produced in France in 1896 and coined the name "Invar". Then when a company in the United States began making it around 1916, they called it "Gamma Steel". I have also seen the word "Minvar" used in regard to certain steel tapes. Perhaps "Invar" tapes were too expensive for those outside of the government agencies to obtain, so they were not sold by the regular equipment suppliers.

Ingram says that c&GS bought their's from J. H. Agar Baugh, London, in 1905

Yes, they bought six of them in December 1905.

I have more recent catalogs from Lufkin and K&E.

Lufkin catalog 201 from 1976 shows Minvar low expansion steel tapes. Four stock numbers 100', 150', 30m and 50m. First two with graduations at 0-50-100 and 0-50-100-150. Metric at 0-15-30m and 0-25-50m. There's an illustration of a tape "wound up" and one enlarged illustration of the 50 graduation. I can't remember when Lufkin stopped manufacturing this series, likely before 1990. I think the cost was probably $1000 or more by then.

K&E Field Equipment Catalog 11 from 1979 shows two LoVar rods. LoVar shows a registered mark. Both are 10ft single section. One graduated feet, 1/10th and 1/100ths. Other graduated yards, 1/10th yds, and 1/100ths yds. Latter was to be used with levels having a .3:100 stadia ratio for three wire leveling. These rods were wood with the graduations on a LoVar strip.

K&E Measuring Tapes Catalog 12 from 1981 does not have a LoVar tape. By this time Rabone Chesterman in England was making the K&E long tapes. K&E was slowly falling apart.

There was a company in Germany making Invar tapes into the late 90's. Again, very expensive. One problem is getting the steel. You can't just make 100' or 30m length of invar steel in the narrow width expected for a measuring tape.

NEDO in Germany is probably the only manufacturer of Invar leveling rods, supplying them to the remaining instrument manufacturers including barcode versions.

In my experience users had the mistaken idea that Invar tapes were more accurate and would want to use them on construction sites and so forth. The Minvar tape with just three graduations would not have been much use unless every measurement was at a graduation mark. The price always scared them off. I heard one story of one actually being used and a truck ran over it, breaking it and rendering it useless. I always suggested buying a good quality steel tape like a Lufkin Peerless, have it certified and use it as a master for comparison of tapes used in the field. You could do the same with Invar. Invar's advantage is its lower thermal coefficient of expansion and contraction. No matter if the tape is invar or ordinary carbon steel corrections for sag, tension and temperature will have to be made if high accuracy is the goal.

Thanks everyone for the information. It is truly an interesting part of our surveying history.

Being a guench-annealed nickle alloy, Invar has the nasty reputation of being susceptible to an unpredictable "jump" in its calibration. Some tapes/level faces do it, and some don't. That's the reason why they're supposed to be re-calibrated/re-certified on a regular basis. Invar has a thermal coefficient of expansion from changes in temperature that is 1/6 th of normal steel. That's why it's favored for ultra-precise measurement.

The first set-ups made for use with Invar was the Jãderin apparatus that combined Invar wires with brass wires. They were intended to be used with clamps specifically manufactured for attaching to railroad rails. The Jãderin apparatus was famously used all over the world in the late 19th century.

Note that there's an umlaut over the "a" in Jãderin.

Among the stuff at LSU between my own gizmos and that of LSU, we have a Lovar 100' tape, two Kern Invar rods (1/2 centimeter), one WILD rod (graduated in feet) and a couple of itty-bitty scales for optical tooling. There's also one invar bar code rod we have in our C4G Research Center.

We used to use USGS surplus invar yard rods. The last ones we had got sent to our surplus about 15 years ago. We ran 3-wire levels with the old yard rods. We currently use centimeter graduated invar rods with a parallel plate micrometer on the level.

The USGS rods were graduated to tenths of a yard. They were also color-coded. From zero to 1 yard the rod had a black background. From 1 to 2 it was colored red. From 2 to 3 it was green, with the 4th yard colored yellow. The back of the rod was graduated in tenths of feet.

The field procedure was for the guy on instrument to read the upper, middle, and lower cross hairs, then call out the colors for the upper and lower crosshairs. When calling out the colors you had to shout loud enough for the rod man to hear since that was the signal for the rod man to turn the rod around so the instrument man could read the back of the rod in feet as a check.

The upper and lower stadia intervals needed to be within 0.003 yard, and with the yard colors, and the sum of the three hairs matching the back of the rod, it was nearly impossible to get a bad set of readings.

okay,....off topic. But isn't a squiggly line over a letter called a "tilde" (ã) and isn't a umlaut two dots over the letter? (ä)

With some further research, I found that Lo-var was a trademark of Kueffel & Esser in the 1930's and Minvar was a product of Lufkin Rule Company in the 1960's. Both companies made low thermal expansion tapes to less rigorous standards and cost than Invar.

Should have put on my glasses when I selected the character symbol. You are correct.

From the above referenced catalogs:

Lufkin 201

"Lufkin Minvar low expansion base line tapes are made from a special alloy. They have an extremely low coefficient of expansion that is 1/30 that of the high quality steel normally used in fine tapes."

This catalog also has a tape thermometer which was a thermometer in a special housing allowing the bulb to touch the tape. Below it in the catalog is a tape corrector thermometer in a steel housing with thongs to attach to the frame of the transit. "Read the thermometer and measure long or short as indicated." Graduations on thermometer appear to be ...+3, +2, +1, -1, -2, -3,...

K&E Catalog 11

"LO-VAR has a very low coefficient of heat expansion, about 1/25 that of carbon steel."

The LO-VAR rod could be ordered with a thermometer mounted in a recess of the rod. It appears the bulb touches the rod face.

My Department-Division-Section has a Zeiss NI-2 level which is setup to be used with a yard rod (the stadia hairs are closer together than normal). It has an old Division of Highways property tag on it. We don't have a yard rod, though.

Pictured above is a photo of the Cooke Troughton & Simms (York, England) precision levelling rod (graduated every 0.02 ft. & figured every 10th of a foot) for use with their S-500 Geodetic Level. CTS referred to the inlaid strip as Nilex. I had wondered why the strip was called Nilex by CTS rather than Invar. Was it the case that with Minar, Lo-Var & Nilex these were different compositions (than Invar) or was there some circumvention of patent rights going on?

MapTack