This is an internal groove comparator gage, made by Kroeplin (Germany) but manufactured in the Czech Republic. You'll find these sold by Mitutoyo, SPI, Dyer Gage and many other distributors who have had their names stamped on the body. The newest version is a decided improvement over what you've probably seen before. The old models, if you ever opened up the back, actually had a piece of common string as part of the mechanism. Subsequent models changed the string to steel wire. Kroeplin has recently introduced some high-precision models which are wholly gear driven. Additionally, older models had a larger range. You may now have to buy two different Intertest gages to cover the same span. The feeler arms typically have a carbide ball braised to their ends. This assures consistent readings over the entire range. Unfortunately, the balls will eventually break off resulting in a costly repair. A few models still have flat (chisel) feeler arms but these wear down unevenly and result in inconsistent readings over time. Since they are made in Europe, the certificates are not NIST traceable but all new models come with a thorough factory certificate of accuracy which is traceable to international length standards. If you need a long form certificate that can be arrange for a fee (and about 2 weeks extra delivery time). 
The measuring depth refers to the length of the measuring arms, shown as L in the diagram above. Note that the arms are thicker near the top, which may make some part of L unusable in small holes under some circumstances. The smallest dimension printed on the dial is also the smallest diameter into which the arms will fit. There is an extra .010" leeway but that can vary and shouldn't be counted on. Dimension A is the maximum depth into which the arm will fit. Dimension B is the maximum width into which the end of the arm will fit. All of these models have the new steel wire construction and carry either the SPI or the Dyer name. Also known as an internal dial caliper gage, the Intertest will measure recesses and grooves where ordinary dial calipers are useless. Although, the gage is designed to be a comparator, it can be used for taking direct readings as well. You should verify its accuracy as often as possible to make sure the readings you are taking are correct. When used as a comparator set the gage to your master piece and then compare it with your work piece. The gage is most accurate when used in this manner, and some manufacturers (Mitutoyo for example) insist that this is the only way to use the gage. It is the user's responsibility to verify accuracy before each use of this gage. Be sure to practice taking readings before the Intertest is actually put into service. You don't want to find out that you've been reading it wrongly after it's too late. The Intertest is available in two range types: the short range and the 1" range. See the selections below.
|
Mitutoyo dial caliper gage - Series 209 |
The Mitutoyo dial caliper gage is identical to these Kroeplin Intertest gages, made by the same manufacturer in Europe. Because Mitutoyo rarely stocks dial caliper gages it will be to your benefit to order one of the equivalent models shown below. We have included the Mitutoyo model number for cross reference.
|
Short Range Intertest |
Kroeplin Model 104-103 (.4-.8" range) with SPI brand name shown above. All models in this category have carbide ball tips with the exception of 104-100 which has a .004" radius tip and model 104-102 which has a .006" radius tip made of fine steel alloy. These radius tips are described as "chisel tips" by some distributors.
|
.0002" graduation with Dimension L = 1.07" |
 | | | | | | | |
Order No. | Range | Mitutoyo
equivalent | Tip | SPI
equivalent | Dimension A | Dimension B | Price USD |
| | | | | | | |
104-100 | .1-.3" | 209-730 | .004" radius | 20-587-2 | .040" | .040" | 509.00 |
104-101 | .2-.4" | 209-731 | .020" ball | 20-588-0 | .094" | .040" | 509.00 |
Above models: linear accuracy full range ±.0004", repeatability .0001" |
| | | | | | | |
.0005" graduation with Dimension L = 2.4" |
| | | | | | | |
104-102 | .2-.6" | 209-732 | .006" radius | 20-589-8 | .094" | .050" | 562.00 |
104-103 | .4-.8" | 209-733 | .040" ball | 20-590-6 | .2" | .040" | 562.00 |
104-104 | .8-1.2" | 209-734 | .040" ball | 20-591-4 | .2" | .040" | 562.00 |
104-105 | 1.2-1.6" | 209-735 | .040" ball | 20-592-2 | .2" | .040" | 562.00 |
104-106 | 1.6-2.0" | 209-736 | .040" ball | 20-593-0 | .2" | .040" | 562.00 |
Above models: linear accuracy full range ±.0008", repeatability .0002" |
| | | | | | | |
0.005 mm with Dimension L - 27 mm |
| | | | | | | |
104-200 | 2,5-7,5 | 209-650 | 0.1 radius | 21-587-1 | 1 mm | 0.55 | 562.00 |
104-201 | 5-10 | 209-651 | 0.6 mm ball | 21-588-9 | 2,4 mm | 0.55 | 562.00 |
Above models: linear accuracy full range ±0.01 mm, repeatability 0.0025 mm |
| | | | | | | |
0.01 mm with Dimension L - 61 mm |
| | | | | | | |
104-202 | 5-15 | 209-652 | 0.15 radius | 21-589-7 | 2,4 mm | 0.76 | 562.00 |
104-203 | 10-20 | 209-653 | 1 mm ball | 21-590-5 | 5.4 mm | 1 | 562.00 |
104-204 | 20-30 | 209-654 | 1 mm ball | 21-591-3 | 5.4 mm | 1 | 562.00 |
104-205 | 30-40 | 209-655 | 1 mm ball | 21-592-1 | 5.4 mm | 1 | 562.00 |
104-206 | 40-50 | 209-656 | 1 mm ball | 21-593-9 | 5.4 mm | 1 | 562.00 |
Above models: linear accuracy full range ±0.02 mm, repeatability 0.005 mm |
| | | | | | | |
Intertest - Long Range |
Kroeplin Intertest model 101-104 (2.8-3.8" range) with Dyer brand name shown above.
The Intertest gages below all have .040" Ø carbide contact balls. Models 101-114 through 101-120 consist of one measuring head complete with 3 to 6 interchangeable contacts. Kroeplin, Dyer, Mitutoyo and SPI are all identical except for the brand name. We give some equivalent model numbers for easy cross-referencing.
|
.0005" graduation with .040" carbide ball contact |
| | | | | | | |
Order No. | Range | Mitutoyo
equivalent | SPI
equivalent | Dim L | Dim A | Dim B | Price USD |
| | | | | | | |
101-100 | .4-1.4" | 209-712 | | 3.15" | .170" | .070" | inquire |
101-101 | 1.0-2.0" | 209-713 | | 3.15" | .230" | .098" | inquire |
101-102 | 1.6-2.6" | 209-760 | 20-556-7 | 3.15" | .230" | .098" | 562.00 |
101-103 | 2.2-3.2" | 209-761 | 20-557-5 | 3.15" | .230" | .098" | 610.00 |
101-104 | 2.8-3.8" | 209-762 | 20-558-3 | 3.15" | .230" | .098" | 650.00 |
101-114 | 3.2-4.2" | 209-763 | | 3.15" | .230" | .098" | inquire |
101-116 | 2.4-5.4" | 209-715 | | 3.15" | .230" | .098" | inquire |
101-117 | 4.7-7.7" | 209-716 | | 3.15" | .230" | .098" | inquire |
Above models: linear accuracy full range ±.001", repeatability .0001" |
| | | | | | | |
.001" graduation with .080" carbide ball contact |
| | | | | | | |
101-118 | 7.1-12.2" | | | 6.9" | .315" | .130" | 1239.00 |
101-119 | 11.8-16.9" | | | 6.9" | .315" | .130" | 1329.00 |
101-120 | 16.5-21.65" | | | 6.9" | .315" | .130" | 1419.00 |
Above models: linear accuracy full range ±.002", repeatability .0005" |
|
0,01 mm graduation with 1 mm carbide ball contact |
| | | | | | | |
101-200 | 10-30 | 209-608 | | 80 | 4.5 mm | 1.8 mm | 689.00 |
101-201 | 20-40 | 209-609 | | 80 | 6 mm | 2.5 mm | 689.00 |
101-202 | 30-50 | 209-600 | | 80 | 6 mm | 2.5 mm | 689.00 |
101-203 | 40-60 | 209-884 | | 80 | 6 mm | 2.5 mm | 689.00 |
101-204 | 50-70 | 209-885 | | 80 | 6 mm | 2.5 mm | 719.00 |
101-205 | 60-80 | 209-886 | | 80 | 6 mm | 2.5 mm | 719.00 |
101-206 | 70-90 | 209-887 | | 80 | 6 mm | 2.5 mm | 719.00 |
Above models: linear accuracy full range ±0.025 mm, repeatability 0.0025 mm |
|
Oditest Dial Caliper Gage |
The same Intertest system designed for external groove measurement, recess diameters and wall thickness. The models below all have carbide balls at the measuring end except for model 20-599-7 which has chisel-shaped arms. Refer to the notes on Intertest above. Special model 301-104 is also available with chisel points or 2" diameter flat contacts for foam, rubber and soft material measurement. |
Order No. | Range | Grads | Accuracy | DimL | Dim A | Dim B | Price USD |
| | | | | | | |
20-597-1 | 0-.2" | .0002" | ±.0001" | 1.10" | 0.31" | .059" | 512.00 |
20-598-9 | 0-.4" | .0005" | ±.00025" | 2.24" | 0.32" | .059" | 512.00 |
20-599-7 | 0-.4" | .0005" | ±.0005" | 2.32" | 0.32" | .039" | 512.00 |
301-104 | 0-1" | .0005" | ±.0005" | 3.3" | | | inquire |
20-580-7 | 0-2" | .001" | ±.002" | 6.8" | 1.25" | .180" | 597.00 |
You may order online by selecting any linked model number. |
|
Intertest Repair |
Repairs are possible on all Intertest and Oditest models except the oldest with the metal bezel and, occasionally, the string-driven models. Missing carbide balls can be replaced. With over 40 years of experience in Intertest and Oditest repairs we are well qualified to perform both repairs and calibration of these tools. Do-it-yourself crystal replacement Bezels and crystals can usually be exchanged by the end user. Some models use a single unit, plastic bezel/crystal combination. There are two different sizes to select from. The older models had a diameter of about 56 mm, the new models have 49 mm. Model 104-103, shown in the photo at the top of this page, illustrates the newer 49 mm bezel/crystal. It would seem to be an easy thing to replace this item. The old crystal can be pried off with a large blade screwdriver. Since rotating the crystal should also cause the dial to rotate, you'll have to line up a plastic tab on the inside of the new crystal with the notch in the dial. In theory, the new crystal snaps back on. Press squarely down on the crystal with the palm of your hand until it's in place. If the Intertest crystal rides on 3 steel balls, which is the case in some very old models, then you'll probably have trouble rotating the dial. You may have to live with this. If it snaps over a plastic o-ring in other old models, the dial may buckle or the whole thing barely fits. Occasionally, several small plastic tabs on the inside of the crystal may have to be filed away for a better fit. There should be no trouble with newer models, though. These crystals aren't cheap, so use caution. - crystal for old models with 56 mm diameter no. KR0562-03 ... $36.50
- crystal for new model with 49 mm diameter no. KR0562-01 ... $36.50
Some of the latest models have simple flat crystals held in place by two movable tolerance marking rings. Model 101-104 shown in the photo on this page, is of this new type. Simply remove the two rings using a small bladed screw driver, or similar tool, and the old crystal can be lifted out. The new crystal is dropped in place and the rings are installed. These parts appear to be made by Kafer. You will want to order crystal #52101 on page 143.
|
The Expensive Version |
The Swiss-made Interapid Hole and Groove Checking Comparator Gage model IRA2 (do not confuse Interapid with Intertest), costing several times more, has the advantage of an extended range, up to six inches, so that one gage will perform the function of many. The measuring anvils are exchangeable and optional accessories allow for 3-point contact measurement as well. See page 22 for details.
|
