Model 1101-C Thermoelectric Metal Tester ________________________________________________________________________________ • Sorts Alloy Scrap • Checks critical welds for location and material • Verifies Parts in Receiving • Easy-to-Use • Inspection for proper alloys • Lightweight • Uses 115V AC, 60 CPS Wall outlet The information contained in this manual is subject Description to change without notice. Acromag, Inc., makes no warranty of any kind with regard to this material, The Acromag Model 1101-C Thermoelectric Metal including, but not limited to, the implied warranties of Tester saves valuable time, and helps prevent costly merchantability and fitness for a particular purpose. mistakes in mixed-up stock, parts, and heat-treat. It Further, Acromag, Inc., assumes no responsibility for is a low-cost way to help sort expensive alloy scrap, any errors that may appear in this manual and verify precision machined parts in receiving makes no commitment to update, or keep current, inspection and check welds. the information contained in this manual. No part of this manual may be copied or reproduced in any The Acromag Metal Tester tests each part in less form, without the prior written consent of Acromag, than 5 seconds. It is a non-destructive test that can Inc. be used on precision bearing surfaces. Readings can be done on any size and shape of object. Best results are obtained when clean, uncorroded and unplated surface finishes are used. Readings taken IMPORTANT SAFETY CONSIDERATIONS from dirty or corroded scrap may differ from readings on clean metal, but with care the Metal Tester can It is very important for the user to consider the supply usable results. possible adverse effects of power, wiring, component, sensor, or software failures in designing The Acromag Metal Tester uses a high precision any type of control or monitoring system. This is solid-state transistor reference temperature especially important where economic property loss controlled probe. Drift is avoided by using a special or human life is involved. It is important that the user magnetic amplifier which provides extremely stable, employ satisfactory overall system design. It is and reliable results. agreed between the Buyer and Acromag, that this is the Buyer's responsibility. - 2 - Model 1101-C Thermoelectric Metal Tester ___________________________________________________________________________________________ The Acromag Metal Tester requires less than five downscale, switch from B to C for your reading. If minutes for the hot probe to reach operating the meter reads upwards off-scale, switch from C temperature. to D. In general, read specimens on the B and C Principle of Operation ranges whenever possible. If readings are off- scale, read on A and D ranges. The Acromag Metal Tester utilizes the same theory as a thermocouple, the Seebeck Effect. A 7. Report readings as C-40, D-52, A-12, etc. thermocouple is formed by paired junctions of two different metals, and when one junction is at a higher temperature than the other, a small voltage is Limitations produced. The amount of voltage varies with the type of metal and how it has been treated, such as Just as metal identification by spark, chemical or rolling, drawing, annealing, etc. magnetic tests is not 100 per cent effective, neither isthermoelectric testing perfect. Some alloys differ The Acromag Metal Tester creates a thermocouple only slightly in one or two elements and the change junction on the specimen by means of copper in voltage on the tester is too slight to produce a electrodes. One electrode, the plate, is at room different reading. Some alloys have elements in temperature, and the other, a probe, is heated to them which may offset one another to produce about 125°C. When the unknown metal specimen is nearly identical readings over all. Alloys of identical chemical makeup, but in different physical hardness placed on the copper plate, and touched with the hot structure, usually have different readings. In spite of probe a complete electric circuit with a small voltage these limitations, the Acromag Metal Tester has is created. A magnetic amplifier drives the built-in proved a valuable aid to identify a wide variety of voltmeter, which has several ranges for easier alloys, for hardness, etc. For example, distinctions reading. have been made between such alloys as: 300-series stainless, monel, K-monel, cobalt base, 400-series How to use the Acromag Metal Tester Model stainless, Inconel, carbon steel, and many of the 1101-C high temperature stellites, Hasteallys, and Nimonics. 1. Attach the hot probe and cold plate to the connectors at the rear of the cabinet, and screw Hints for Repeatable Readings on firmly. 1. Hold the probe as shown in the photo. Rocking 2. Plug the unit into a 115V AC, 60 CPS power the probe changes reading slightly. Avoid striking source. The unit uses only 30 Watts. or hitting the probe. 3. Rotate the function switch from OFF to position B. 2. Clean metal specimens well. If necessary, clean The green “Power” led should light up the hot probe tip with very fine sandpaper, and immediately showing the power is on. wipe clean with a clean dry cloth. Avoid cleaning the probe tip more often than needed as this 4. After approximately five minutes, the yellow hastens wear and replacement. Be sure to clean “Ready” led will start to flicker on and off. This metal specimen well, and wipe very clean. means that the instrument is warmed-up and Failure to remove metal and dirt particles from ready to use. the specimen causes them to imbed into the tip. This causes very erratic readings. It is then 5. Place a clean metal specimen on the cold plate necessary to re-polish and clean the probe tip and gently place the hot probe on the specimen. with fine sandpaper. Never use emery cloth. Then apply a moderate pressure of a few pounds. IMPORTANT: Do not strike or hit the 3. It is necessary to clean the hot probe tip specimen as this tends to flatten the smooth occasionally with very fine sandpaper. Then wipe round tip on the hot probe which causes erratic clean. This removes normal surface oxides, and readings and excessive wear. surface contamination picked up from metal specimens. 6. Read the meter and record. If the meter reads upwards off-scale, change the function switch 4. At least 25,000 measurements are practical from B to A for the reading. If the meter reads before the hot probe needs rebuilding. With care, - 3 - Model 1101-C Thermoelectric Metal Tester ___________________________________________________________________________________________ more than 100 thousand measurements are Calibration Procedure possible before complete probe reconditioning is necessary. Acromag Model 1101-C Metal Testers have an 5. Some specimens, such as aluminum, may adjustment to allow calibration to obtain a specific appear clean, but actually have surface oxides reading on a specific sample. This adjustment that cause false and erratic readings. Three allows gain trim of several percent on the internal preliminary readings within a one-inch circle of meter amplifier. To calibrate, turn instrument on cleaned specimen should agree within two or allowing several minutes to warm up. Once the three fine scale markings. If these readings do ready light begins cycling, the unit is ready to not agree, reclean the specimen and/or the probe calibrate. One adjustment effects all ranges. Place tip. the known specimen on the plate and apply the probe. Insert a small screwdriver through the hole 6. Painted, anodized, passivated, and plated and adjust the range potentiometer to give the desired reading. An adjustment of approximately 10 specimens must have protective coatings percent is possible. removed prior to testing. Otherwise the instrument reads a mixture of the surface and underneath metal, and readings tend to drift erratically. Experimental tests of cleaned and Repair and Warranty Service non-cleaned specimens have determined the need for cleaning. Free Test Specimen Service Acromag offers a special testing to assist you in determining if an Acromag Metal Tester will solve BOTTOM VIEW your particular needs. Simply send a reasonable number of small specimens to the Acromag Sales Department. We will report the Metal Tester readings to you for evaluation. GAIN ADJUSTMENT Specimen size and shape are not critical, but they should be smooth, and at least as large as a dime. Please identify each one clearly. If specimens are cut from larger pieces, avoid using heat. This sometimes causes localizes heat treat which alters the Metal Tester readings. METER The Acromag Metal Tester contains solidstate components and requires very little maintenance except annual cleaning and check-up. If problems do arise, return the unit with a full description of the problem. All units returned to Acromag for repair must be shipped prepaid. The Metal Tester should be packaged with at least six inches of material to protect it. Repairs caused by shipping damage or normal wear, are not covered by warranty. Contact Acromag Customer Service Department for ordering information, and estimates on repair time. - 4 -