Table of Contents
Related Manuals for Wahl Heat-Prober 2500MX
Summary of Contents for Wahl Heat-Prober 2500MX
- Page 1 ® HEAT-PROBER PORTABLE THERMOCOUPLE THERMOMETERS INSTRUCTION MANUAL LCD Models LED Models TCMR-KX 2500MX 1370MX 2500M TCMRK-VX 2500MVX 1370MVX 1370M 3200MX 1770MX 3200M 3200MVX 1770MVX 1770M W-683 Rev G TCMR-K Revised 02/03/23...
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Page 2: Receiving Inspection
Then, plug in the probe at top and turn it on to see that it reads room temperature. If a fault is determined, take the following steps: 1. Notify the Wahl factory of the difficulty. Give model number and description. Wahl will authorize return, and notify our service department to receive the unit. -
Page 3: Table Of Contents
Low Battery Adjustment ......17 Calibration Using Wahl Calibrator ....18 5.3.1... - Page 4 Heat Prober Thermocouple Types, Model Numbers ..8 Figure 3-2 Standard Wahl Probes ......10 Figure 3-3 Extension Probe Handle .
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Page 5: Introduction
The instrument contains the unique Wahl MAXI-TEMP® digital peak circuit, which gives the user the option to hold the highest temperature sensed. The peak-hold circuit is achieved by the microprocessor scanning the probe input temperature to determine the highest temperature reached. - Page 6 Figure 1.1. Microprocessor Based Thermocouple Digital Thermometer (LED display, left; LCD display, right)
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Page 7: Operation
3-position; the lower detent is marked “N” for normal temperature monitor- ing, the middle detent is “OFF’ and the upper detent is marked “P” for use with Wahl Maxi-Temp peak hold circuit. This tracks the temperature and holds the highest attained reading. - Page 8 Figure 2-1. Digital Heat-Prober Major Features...
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Page 9: Meter Operation
10% charge per week. If the battery fails to respond to recharge, provisions have been made for ease of replacement. Open the back cover and disconnect from the instrument by means of the Molex connector. Replace with Wahl P/N 11681 (See Figure 2-2). - Page 10 Figure 2-2. Replaceable 9V Battery Pack Compartment (above) Rechargeable Battery Pack Compartment (below)
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Page 11: Recharging
2.3.1 Recharging To recharge the batteries, use the recharger supplied. Plug in directly to a 120-volt, 60-cycle wall plug and insert the jack into the socket on the left side of the Heat- Prober. (For overseas 220-volt lines, use a Franzus converter adapter with the recharg- er supplied or request a 220-volt recharger). -
Page 12: Probes
3.0 PROBES One of the key features of the Wahl Thermocouple Heat-Prober is a standard miniature thermocouple connector used in the meter. Thermocouple connections are color coded by type. Use probes with the same color male plug as the female. Each Heat- Prober is designed for use with a specific thermocouple Type K or S. - Page 13 If such use is needed consult the fac- tory for a special design. Wahl specializes in surface temperature measurement probes. Models TC808, 809, and 810 are exposed element surface probes for fast surface temperature measure- ments.
- Page 14 Figure 3-2. Standard Wahl Probes Figure 3-3. Extension Probe Handle...
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Page 15: Open Probe
Thermocouple Type K (Model TC830): For 2500°F (1370°C) with expendable type K tips. Useful for molten non-ferrous metals. The meter is removable from the handle and therefore can be used elsewhere with any of the other Wahl probes. Thermocouple Type S (Model TC840): For 3200°F (1770°C) in very high temperature iron and steel melts. - Page 16 Figure 3-4. Molten Metal Dipstick...
- Page 17 Wahl’s surface probes are designed with the above conditions as criteria. They also include an insulating handle for your safety and convenience. Each probe is assembled with a plastic handle made of high-quality Delrin which: a) Thermally isolates the hand from the probe, preventing hand heat from reaching the sensor, and sensor heat, in the case of high temperature meas- urement, from burning the hand.
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Page 18: Specifications
SPECIFICATIONS Temperature Measurement Range Model T/C Type Range Display T/C 2500M -100 to 2500° T/C 2500MX -100 to 2500° T/C 2500MVX -100 to 2500° T/C 1370M -70 to 1370° T/C 1370MX -70 to 1370° T/C 1370MVX -70 to 1370° T/C 3200M 77 to 3200°... - Page 19 Display: 0.3” high LED, 0.4. High LCD Automatic Polarity Indication Open Probe: Indicated by “OL” Low Battery: Indicated By “L” on LED “LOW BAT”, or “←”, Annunciator on LCD Update Rate: 2.5/Sec. Resolution: ±1 Repeatability: ±1°F, ±1 digit Accuracy: ±.2% Reading ±1 digit Thermocouple Probe: Standard miniature thermocouple connector Connections:...
- Page 20 Recharger: 7.5V @ 120mA from 11Ovac line. Continuously operable from recharger through Line Operation: internal batteries. Effects of High AC No damage or display effect at 120 vac.No damage at 500 vac Voltage on Probe: Size and Weight: 3” wide x 6” long x 11/2” high. 12 oz. (7.5cm x 15cm x 3.7 cm;...
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Page 21: Calibration
5.0 CALIBRATION Be sure to allow the Heat-Prober to stabilize to room temperature for at least 30 minutes before calibration procedure is begun. It is important that all the compo- nents be stabilized to room temperature, especially those involved with cold junction compensation. -
Page 22: Calibration Using Wahl Calibrator
1 ) Set the Wahl calibrator to its maximum temperature setting. Adjust the span with resistor R22. The display should read the highest temperature indication on the Wahl calibrator (to which it has just been set), plus the room temperature. - Page 23 2) See Figure 5-3 for LED and Figure 5-4 for LCD adjustment points. Short the thermocouple connector with a copper wire. With the input shorted, the input voltage to the electronics is zero, and only the reference junction compensation circuit contributes to the signal used to compute tempera- ture.
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Page 24: Span Adjustment With Millivolt Source
5.4.2 Span Adjustment with Millivolt Source 1) Insert copper wires into the thermocouple probe socket to apply the milli- volt signal. A calibration temperature should be chosen so that it is at the high end of the temperature range of the instrument (within about 10% of the upper limit of the range). -
Page 25: Thermal Calibration
1370°C. Therefore, the above “thermal calibration” may actually introduce an error into the meter because it is being calibrated to a thermocouple with an error in it. Wahl thermocouple probes are precalibrated at 2 temperatures with an acceptable tolerance of ±O.1°F/C. -
Page 26: Calibration With Thermocouple Simulator
32°F, the actual output temperature of the TA-70 will be 70° + 32° = 102°F. For the most accurate calibration of ambient temperature, utilize a thermometer with accuracy of 0.5° traceable to NIST. Wahl’s 392M Platinum RTD meter with a 202... - Page 27 Batteries may be replaced or measured by removing the four cover retaining screws and carefully lifting off the cover. The battery may be removed from the holder and replaced with a Wahl Instruments battery, part number 9782-9. TA70 ACCURACY SPECIFICATIONS...
- Page 28 Figure 5-2. Heat-Prober with Wahl Calibrator...
- Page 29 Figure 5-3. LED Adjustment Points...
- Page 30 Figure 5 - 4. LCD Adjustment Points...
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Page 31: Theory Of Operation
6.0 THEORY OF OPERATION For General Description of Wahl Microprocessor Circuit Thermocouple Heat-Prober (See Figure 6-1). The Wahl Thermocouple Heat-Prober can be used with Type K and S thermocouple probes terminated in a standard male miniature connector. The female portion of the connector has a special temperature sensing diode encased in it to measure the ambient temperature of the connector and, therefore, compensate for cold junction. - Page 32 Figure 6-1. Program Flow Chart...
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Page 33: Voltage Regulation Circuitry
6.1 Voltage Regulation Circuitry The battery voltage of approximately 6.5 volts is regulated down to 5 volts by Q1 and U2 in conjunction with U1 which is used for its internal zener. When power is first applied, the PNP transistor (Q1) turns on sourcing current into the system load con- sisting in part of R19, R20, and R21. -
Page 34: Cold Junction Compensation
6.4 Cold Junction Compensation The thermocouple output is a function of the difference in temperature between its probe and end copper connection junction (cold junction). In case of Type K material, the output is 40 microvolts per degree C. Since the microprocessor’s temperature con- version tables contain reference thermocouple values to ice point and the actual con- nection is at ambient temperature, the temperature difference must be accounted for by a compensation circuit. -
Page 35: 8048 Microprocessor
6.6 8048 Microprocessor The 8 bit signal chip 8048 microprocessor is configured with P1 as the analog-to-digi- tal input port, P2 as a control/status port, and the b-directional data port, DB, as the display driver output port. Test ports T1 and T2 are used to sense the LED/LCD config- uration flag and the peak hold request respectively. -
Page 36: Low Battery Indication
Figure 6-2. Microprocessor Control Functions 6.8 Low Battery Indication The circuitry is powered by a pack of five Ni-Cad rechargeable batteries. When the bat- teries discharge to a point where the circuitry will soon malfunction, U2 switches on positive and drives the low battery indicator of the display. This occurs at a battery voltage of approximately 5.6 Vdc. - Page 37 The best way to check the functioning and calibration condition of the Heat-Prober is to use the Wahl Accessory Calibrator for your particular type of thermocouple heat prober (Type K or S). See Figure 5-1. These units plug directly into the probe connec- tion and provide the proper calibration points.
- Page 38 Some of the troubles that may occur are identified below, along with corrective action. PROBLEM/SYMPTOM POSSIBLE CAUSE CORRECTIVE ACTION 1-1 Press switch again. 1-1 Switch may not be fully on. 1-2 Recharge batteries. 1. Switch on, probe in, but no 1-2 Batteries are discharged.
- Page 39 PROBLEM/SYMPTOM POSSIBLE CAUSE CORRECTIVE ACTION 6-1 Recharge battery or replace. 6-1 Battery is dead. 6. No reading at all when 6-2 Return to factory for repair switch is turned on. 6-2 Internal fault. or refer to diagnostics (Sec. 8.0). 7-1 Disconnect probe. Use calibrator and check 4 7-1 Heat-Prober is out of 7.
- Page 40 8.0 MAINTENANCE & REPAIR Before proceeding with this section, be sure that the basic troubleshooting steps in Section 7.0 have been followed. This section describes diagnostics to find the majority of problems for malfunctioning units. See Figure 8-1 for Block Diagram and Figure 7-1 for wiring diagram. Equipment Required: 1 ) 4 1/2-digit DVM: Fluke 8600A or equivalent.
- Page 41 Step Problem Action to be Performed If Corrected If I ncorrect Blank Measure U2-7 irregular or Should be +3.90V Proceed to next step Replace U2 incomplete Adjust R20 for 3.90V display if necessary Check CR7, CR6, and CR13 Replace defective Proceed to next step to see if they are open component...
- Page 42 Step Problem Action to be Performed If Corrected If I ncorrect Unit Check voltage at U5-34. It constantly should be between 0 and Proceed to step 17 Proceed to next step reads -3.5V “-OL-” Input millivolt equivalence to reach full scale rating of instrument.
- Page 43 Figure 8-1. Block Diagram...
- Page 44 Figure 8-2. LED Component Layout...
- Page 45 Figure 8-3. LCD Component Layout...
- Page 46 9.0 IPTS-68 TABLES, TYPE K THERMOCOUPLES – °F °F °F 32.0 0.0000 78.0 1.0227 33.0 0.0219 79.0 1.0452 34.0 0.0439 80.0 1.0677 35.0 0.0659 81.0 1.0903 36.0 0.0878 82.0 1.1128 37.0 0.1098 83.0 1.1354 38.0 0.1318 84.0 1.1579 39.0 0.1539 85.0 1.1805 40.0...
- Page 47 9.0 IPTS-68 TABLES, TYPE K THERMOCOUPLES – °C °C °C 0.0000 45.0 1.8166 0.0395 46.0 1.8577 0.0790 47.0 1.8989 0.1186 48.0 1.9400 0.1583 49.0 1.9812 0.1979 50.0 2.0224 0.2377 0.2774 0.3172 0.3571 10.0 0.3970 11.0 0.4369 12.0 0.4769 13.0 0.5169 14.0 0.5570 15.0...
- Page 48 ITS-90 TABLES, TYPE K THERMOCOUPLES – °F °F °F 32.0 0.0000 78.0 1.0228 33.0 0.0219 79.0 1.0453 34.0 0.0439 80.0 1.0678 35.0 0.0658 81.0 1.0904 36.0 0.0878 82.0 1.1129 37.0 0.1098 83.0 1.1355 38.0 0.1318 84.0 1.1581 39.0 0.1538 85.0 1.1807 40.0 0.1758...
- Page 49 ITS-90 TABLES, TYPE K THERMOCOUPLES – °C °C °C 0.0000 45.0 1.8171 0.0395 46.0 1.8583 0.0790 47.0 1.8994 0.1186 48.0 1.9406 0.1582 49.0 1.9818 0.1979 50.0 2.0231 0.2376 0.2773 0.3171 0.3570 10.0 0.3969 11.0 0.4368 12.0 0.4768 13.0 0.5168 14.0 0.5569 15.0 0.5970...
- Page 50 IPTS-68 TABLES, TYPE S THERMOCOUPLES – °F °F °F 32.0 0.0000 78.0 0.1458 33.0 0.0030 79.0 0.1491 34.0 0.0060 80.0 0.1525 35.0 0.0090 81.0 0.1558 36.0 0.0121 82.0 0.1592 37.0 0.0151 83.0 0.1625 38.0 0.0181 84.0 0.1659 39.0 0.0212 85.0 0.1693 40.0 0.0242...
- Page 51 IPTS-68 TABLES, TYPE S THERMOCOUPLES – °C °C ° C 0.0000 46.0 0.2728 0.0054 47.0 0.2792 0.0108 48.0 0.2857 0.0163 49.0 0.2922 0.0218 50.0 0.2986 0.0273 0.0328 0.0384 0.0440 0.0496 10.0 0.0552 11.0 0.0609 12.0 0.0666 13.0 0.0723 14.0 0.0780 15.0 0.0837 16.0...
- Page 52 ITS-90 TABLES, TYPE S THERMOCOUPLES – °F °F °F 32.0 0.0000 78.0 0.1459 33.0 0.0030 79.0 0.1493 34.0 0.0060 80.0 0.1526 35.0 0.0090 81.0 0.1560 36.0 0.0121 82.0 0.1593 37.0 0.0151 83.0 0.1627 38.0 0.0181 84.0 0.1661 39.0 0.0212 85.0 0.1694 40.0 0.0243...
- Page 53 ITS-90 TABLES, TYPE S THERMOCOUPLES – °C °C °C 0.0000 46.0 1.2731 0.0054 47.0 1.2795 0.0109 48.0 1.2860 0.0163 49.0 1.2924 0.0218 50.0 2.2989 0.0273 0.0329 0.0384 0.0440 0.0496 10.0 0.0553 11.0 0.0609 12.0 0.0666 13.0 0.0723 14.0 0.0780 15.0 0.0838 16.0 0.0896...
- Page 54 Figure 11-1. 2500M Accessories and Special Purpose Probes...
- Page 55 10.0 ADDITIONAL PROBES AND ACCESSORIES Wahl offers a complete line of probes and accessories to complement the 2500M meter, including: Probes: TC804 Miniature Spring Loaded J-Probe TC812 Ferrous Magnetic Surface Probe, 450°F Magnetic Surface Probe, Ferrous surfaces TC886 Moving Surface Probe, 450°F max...
- Page 56 11.0 RETURN FOR REPAIR/CALIBRATION SERVICE Warranty Repair Information Form Please contact Wahl Customer Service at (800) 421-2853 for a return Merchandise Authorization number (RMA) before returning your instrument to the factory. For calibration, service or technical support, contact: Palmer Wahl 234 Old Weaverville Road Asheville, NC 28804 Ph.: 800-421-2853 (US only) 828.658.3131...