Related Manuals for Fluke 525A
Summary of Contents for Fluke 525A
- Page 1 ® 525A Temperature/Pressure Calibrator Service Manual PN 1644492 March 2002 © 2002 Fluke Corporation. All rights reserved. Printed in USA All product names are trademarks of their respective companies.
- Page 2 Fluke authorized resellers shall extend this warranty on new and unused products to end-user customers only but have no authority to extend a greater or different warranty on behalf of Fluke. Warranty support is available only if product is purchased through a Fluke authorized sales outlet or Buyer has paid the applicable international price.
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Page 3: Table Of Contents
Table of Contents Title Page Introduction ....................... 1 Contacting Fluke ....................1 Safety Information..................... 1 Calibrator Specifications ................... 3 General Specifications .................. 3 DC Voltage Specifications, Output............... 4 DC Current Specifications, Output ............... 4 Resistance Specifications, Output ..............5 Resistance Specifications, Input..............5 Thermocouple Specification, Output and Input .......... - Page 4 525A Service Manual Testing DC Current ..................25 Testing Thermocouple Output ..............26 Testing CJC (Cold Junction Compensation)..........27 CJC (Cold Junction Compensation) Calibration........27 Testing Thermocouple Input ................. 28 Testing Ohms Output ..................29 Testing Ohms Input..................30 Testing Pressure Modules ................32 Calibration Adjustment ..................
- Page 5 List of Tables Table Title Page Symbols Used on the Calibrator ................2 Replacement Fuses ....................13 Front Panel Wire Color Assignments ..............16 Rear Panel Wire Color Assignments ..............16 Output Block to Main PCA Connections............... 17 TC PCA to Main PCA Connections ..............18 Opto RS232 to Main PCA Connections ..............
- Page 6 525A Service Manual...
- Page 7 Testing TC Output ....................26 Connections for CJC Calibration ................27 Connections for Measuring TC Input ..............28 Connection for Measuring Resistance Output ............29 1281 Connection Diagram ..................30 Connection for Measuring Ohms................31 Exploded View of the 525A .................. 46...
- Page 8 525A Service Manual...
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Page 9: Introduction
Calibrator’s functionality and calibration, basic maintenance, contacting Fluke service centers, and important safety information are also contained within this manual. Contacting Fluke To contact Fluke, order accessories, or locate the nearest Fluke Service Center or distributor, call: • USA: 1-888-99-FLUKE (1-888-993-5853) •... - Page 10 525A Service Manual Warning To avoid possible electric shock or personal injury, follow these guidelines: • Use the Calibrator only as specified in this manual or the protection provided by the Calibrator might be impaired. • Inspect the Calibrator before use. Do not use the Calibrator if it appears damaged.
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Page 11: Calibrator Specifications
525A Calibrator Specifications Calibrator Specifications General Specifications Warm up time Twice the time since last warmed up, to a maximum of 30 minutes Settling time Less than 5 seconds for all functions and ranges except as noted Standard interface RS-232... -
Page 12: Dc Voltage Specifications, Output
525A Service Manual DC Voltage Specifications, Output Absolute Uncertainty, tcal ±5 °C ± (ppm of output +µV) Stability 24 hours, ±1 °C Maximum Ranges ± (ppm of output +µV) Resolution Burden 90 days 1 year 1 µV 0 to 100.000 mV... -
Page 13: Resistance Specifications, Output
525A Calibrator Specifications Resistance Specifications, Output Absolute Uncertainty, tcal ±5 °C, ±(ppm of output ± Ω) Ranges Resolution Allowable Current 90 days 1 year 5 to 400.00 Ω 0.01 Ω 0.025 0.03 1 to 10 mA 0.1 Ω 250 µA to 1 mA 5 to 4.0000 kΩ... -
Page 14: Thermocouple Specification, Output And Input
525A Service Manual Thermocouple Specification, Output and Input Absolute Uncertainty, tcal ±5 °C, ±(°C) Range (°C) Output/Input TC Type Minimum Maximum 90 days 1 year 600 °C 800 °C 0.42 °C 0.46 °C 800 °C 1000 °C 0.39 °C 0.39 °C 1000 °C... -
Page 15: Tc Mv Specifications, Input And Output
525A Calibrator Specifications Thermocouple Specification, Output and Input (continued) Absolute Uncertainty, tcal ±5 °C, ±(°C) Range (°C) Output/Input TC Type Minimum Maximum 90 days 1 year 0 °C 250 °C 0.58 °C 0.58 °C 250 °C 400 °C 0.34 °C 0.35 °C... -
Page 16: Rtd And Thermistor Specification, Output
525A Service Manual RTD and Thermistor Specification, Output Absolute Uncertainty tcal ±5 °C, ±(°C) Range (°C) RTD Type Minimum Maximum 90 days 1 year Pt 385, 100 Ω -200 °C -80 °C 0.06 °C 0.07 °C -80 °C 0 °C 0.08 °C... -
Page 17: Rtd And Thermistor Specification, Input
525A Calibrator Specifications RTD and Thermistor Specification, Output (continued) Absolute Uncertainty tcal ±5 °C, ±(°C) Range (°C) RTD Type Minimum Maximum 90 days 1 year Pt 385, 1000 Ω -200 °C -80 °C 0.06 °C 0.07 °C -80 °C 0 °C 0.06 °C... - Page 18 525A Service Manual RTD and Thermistor Specification, Input (continued) Absolute Uncertainty, tcal ±5 °C, ±(°C) Range (°C) RTD Type Minimum Maximum 90 days 1 year Pt 385, 500 Ω -200 °C -80 °C 0.046 °C 0.047 °C -80 °C 0 °C 0.049 °C...
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Page 19: Pressure Measurement
Micro-Controller Section The Atmel ATmega 103 micro-controller is the heart of the 525A. It contains all of the program memory, nv-ram, FlashROM, static RAM, and EEProm. The micro-controller allows a minimal amount of external glue logic. The main external digital ICs are the RS- 232 driver, relay drivers, LCD controller, and the digitally controlled analog switches. -
Page 20: Analog Section
525A Service Manual Analog Section The Calibrator can source DC voltage to 100 V, DC current to 100 mA, resistances from 5 to 4000 Ω, and thermocouples and RTDs. The main components of the analog circuit consist of a precision 2.5-volt temperature compensated reference, 20-bit DAC and a 24-bit ADC. Precision metal foil resistor networks and several chopper-stabilized OP-AMPS are the most critical analog components. -
Page 21: To Check Or Replace A Fuse
525A Basic Maintenance To Check or Replace a Fuse 1. Disconnect line power. 2. Using a flat-blade screwdriver, pry the tab at the base of the line fuse compartment. The compartment cover will pop part way out. 3. Remove the compartment cover. The fuses come out with the compartment cover and can easily be checked or replaced. -
Page 22: Modular-Level Maintenance
525A Service Manual Line voltage indicator Changing line fuse Line fuse compartment Rotate to change line voltage indicator Changing line voltage ajr12f.eps Figure 1. Accessing the Fuse Modular-Level Maintenance XWarning Do not attempt to complete the following procedures unless qualified to do so. This information is for use by qualified personnel only. -
Page 23: Disassembly
There are two wire sets available from Fluke. These wire sets are used to connect the circuit boards. One set is for the front connections and the other set is for the rear panel connections. - Page 24 525A Service Manual Table 3. Front Panel Wire Color Assignments Gage Wire Number Color (all lengths are 6 inches) 24 g Wire Black 24 g Wire Purple 20 g Wire * J 17 Grey 20 g Wire * J18 (1st 6 inches)
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Page 25: Output Block Subassembly Connections
525A Modular-Level Maintenance Ribbon wire Purple wire Yellow Yellow wire wire Blue wire Red wire Grey Blue wire Green wire wire wires Purple wire aby01f.eps Figure 2. Wiring Connections Output Block Subassembly Connections Table 5 lists the connections to be made when connecting the Output Block to the Main PCA. - Page 26 525A Service Manual The TC PCA needs to be connected to the Main PCA. Use the wire connections listed in Table 6. These connections require soldering. Refer to Figure 3. Table 6. TC PCA to Main PCA Connections Solder From TC PCA...
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Page 27: Keypad To Main Pcb
525A Modular-Level Maintenance Keypad PCA to Main PCA To connect the Keypad PCA to the Main PCA, solder the following connections (refer to Figure 4): 1. Solder the 12-conductor cable to the back of the Keypad PCA with pin 1 on the cable aligned with pin 1 on the Keypad PCA. -
Page 28: Opto Rs232 To Main Pca
525A Service Manual Opto RS232 PCA to Main PCA Use 4 wires to connect the Opto RS232 PCA to the Main PCA. Refer to Table 7 and Figure 5. Table 7. Opto RS232 to Main PCA Connections Main PCA Opto RS232... -
Page 29: Reinstalling The Circuit Boards
525A Modular-Level Maintenance Reinstalling the Circuit Boards 1. Place the Main PCA with all its attachments into the chassis base. 2. Put the Output Block into place in the front of the chassis. 3. Use five nylock nuts to secure the Output Block to the Chassis Base. -
Page 30: Final Assembly And Inspection
525A Service Manual wires Green wire Top view Red wires Green wire aby05f.eps Figure 6. Power Module Connections Final Assembly and Inspection To complete final assembly and inspection, use a digital multimeter and verify the continuity of the connections listed in Table 9. -
Page 31: Performance Tests
The following performance tests are used to verify the functionality of the Calibrator. If the Calibrator fails any part of the performance tests, calibration adjustment or repair by a Fluke Service Center is in order. For a list of service centers, refer to "Contacting Fluke" earlier in this manual. -
Page 32: Testing Dc Voltage
525A Service Manual Testing DC Voltage The DC voltage amplitude accuracy test verifies the accuracy of DC voltage at the 525A calibrator front panel Volts Source output. See Table 11. Table 11. Testing DC Voltage Nominal Measured 90 Day Spec. -
Page 33: Testing Dc Current
Performance Tests Testing DC Current Use the Wavetek 1281 and the precision shunt to measure the 525A output as shown in Figure 7. Take the Voltage reading from the Wavetek 1281 and divide it by the 742A-1 actual value. See Table 12. -
Page 34: Testing Thermocouple Output
CJC test, all functions of the TC output will have been checked. Typically, the cable needs to connect the 525A to the 1281 and will need to be fabricated. The TC mini- connector will need to be copper - copper (white). Using copper wire, connect the TC mini-connector to standard banana jacks. -
Page 35: Testing Cjc (Cold Junction Compensation)
Connect a Type-J thermocouple to the TC terminal on the 525A. Immerse the thermocouple and a precision thermometer into a mineral oil lag bath. The test set-up is shown in Figure 9. Verify that the readings of the 525A and the precision thermometer are within the Type-J specifications: •... -
Page 36: Testing Thermocouple Input
Set the 525A to TC input by pressing I then 7. All other 525A conditions will be the same as the thermocouple output test, CJC off, mV/°C mode. Connect the 525A to the 5520A as shown in Figure 10. Set the 5520A to output the mV values in Table 13. -
Page 37: Testing Ohms Output
525A Performance Tests Testing Ohms Output Use the precision digital multimeter (DMM) to measure the resistance output. Figure 11 shows the four-wire connections. See Table 14. Note The Wavetek 1281 must be in the “loI” (low current mode) when measuring 5 Ω... -
Page 38: Testing Ohms Input
525A Service Manual Testing Ohms Input Before measuring ohms input, the ohms output of a 5520A must be “characterized”. To achieve the needed accuracy, the Wavetek 1281 is used as a transfer standard and the 742A is used as the reference standard. To find the true value of the 5520A output, the ratio-input function of the Wavetek 1281 is used. -
Page 40: Testing Pressure Modules
Service Manual Testing Pressure Modules The Fluke 700 series pressure modules are calibrated separately from the 525A. The calibration follows the pressure module, so only a performance test is needed. Connect any of the Fluke 700 series pressure modules to the pressure module connector. Verify that the Calibrator reads pressure. -
Page 41: Adjustment Sequence
525A Calibration Adjustment The password is 525. Enter the password through the PC keyboard and the following is displayed on the PC monitor: Calibration Menu: 1: 100 mV Source 2: 1 V Source 3: 10 V Source 4: 100 V Source... -
Page 42: 14: Calibrate Dac, Digital To Analog Converter Adjustment
525A Service Manual 14: Calibrate DAC, Digital to Analog Converter Adjustment If all of the functions that are affected by the digital to analog converter (DAC) adjustment are going to be adjusted, start with step 14 which adjusts the DAC. Do not adjust the DAC unless all of the ranges affected are going to be readjusted. -
Page 43: 5: 100 Ma Source, Adjusting Dc Current Source
525A Calibration Adjustment The PC display shows: Please Wait… 25755 Adjust to 25 Percent of Scale, 8 for up 2 for down, Press Enter When Stable The value is the raw A/D counts for this calibration point, followed by a prompt to adjust the 25 % of scale value. - Page 44 525A Service Manual The voltage is measured across a 10 Ω shunt resistor instead of measuring current directly. Readings taken from the DMM need to be converted to mA (multiplied by 100) before they can be entered in at the PC.
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Page 45: 6: Hi Ohms Source, Adjusting High Resistance Source
525A Calibration Adjustment Please Wait… 2147203 Adjust to 50 Percent of Scale, 8 for up 2 for down, Press Enter When Stable The value is the raw A/D counts for this calibration point followed by a prompt to adjust the 50 % of scale value. Use the 8 (up) and 2 (down) key on the PC to adjust the output to get a reading very close to 50 % of the range full scale. -
Page 46: 7: Low Ohms, Adjusting Low Ohms Source
Calibrator Wavetek 1281 1. Insert a 4-wire short into the 525A 4W RTD Ω jacks. 2. Type 8 then press the Enter key on the PC. The following will show on the PC: Input 0 Ohms, Press Enter When Stable 3. - Page 47 Connect the low side (LO) of the DMM sense input to the high side of the sense output of the 5520A. 3. Connect the 525A to the 5520A as follows: a. Connect the HI INPUT 4W RTD Ω jack of the Calibrator to the high side of the current input of the 5520A.
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Page 48: 9: Low Ohms, Adjusting Low Resistance Measure
Connect LO INPUT 4W RTD Ω jack of the 525A to the low side of the current input of the 5520A. c. Connect the HI SENSE 4W RTD Ω jack of the 525A to the high side of the sense output of the 5520A. -
Page 49: 10: Sprt 25, Adjusting Sprt Low Resistance Measure
The SPRT 25 range is used for measuring SPRTs (typically 25 Ohm R0) and Ohms from 0 to 100 Ohms in the 0-400 Ohms range. The 525A will measure a short, and 2 resistances. Refer to Table 21 for a list of equipment used in this section. - Page 50 Connect LO INPUT 4W RTD Ω jack of the 525A to the low side of the current input of the 5520A. c. Connect the HI SENSE 4W RTD Ω jack of the 525A to the high side of the sense output of the 5520A.
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Page 51: 11: Tc Source, Adjusting Tc Mvolt Source
The adjust of the TC Source output range is similar to the first part of the voltage source calibration, the 525A outputs two Adjust points, after the output becomes stable the values can be entered at the PC. Refer to Table 22 for a list of equipment used in this section. - Page 52 Service Manual Use a copper TC mini-plug cable with low thermal EMF jacks on the other end to connect the 525A to the DMM. Make certain the polarity is correct. 1. Set the DMM to read DC Volts. 2. Type 12 and press the Enter key on the PC. The following is displayed on the PC: Adjust to -10 mV, 8 for up 2 for down, Press Enter When Stable 3.
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Page 53: Customer Replaceable Parts
525A Customer Replaceable Parts that a reading very close to 75 mV is obtained. When satisfied with the reading, press the Enter key. The PC display will show: Please Wait... 8054372 12. After the raw A/D counts are displayed, the calibration step is complete. The calibration constants for the range have been saved. - Page 54 525A Service Manual ajr20f.eps Figure 14. Exploded View of the 525A...
- Page 55 Customer Replaceable Parts Table 25. Replacement Parts Part Item # Number Description Location Quantity 1601576 525A Front Panel Decal Front Of Top Chassis 1617918 Fuse Drawer Power Module 1645311 Fuse, (1/4A), FB For 1x0 VAC Fuse Drawer 1645327 Fuse, (1/8A), FB For 2x0 VAC...
- Page 56 Not shown 1601541 525A Getting Started Guide Not shown 1601552 525A User Manual (on CD) W For safety, use exact replacement only. * PEP is an exchange of a repairable assembly for a factory repaired one. Table 26. Accessories Description...