Doc: 1150-03-3057 Rev: 24 Apr 2014
Calibration Procedure
HI-1501 Microwave Survey Meter
1. Scope:
1.1. The purpose of these instructions is to ensure proper setup and calibration of Microwave Probes. Calibrations completed using this document will provide traceable and accurate ETS-Lindgren Calibration Laboratory calibrations under the guidelines stipulated by IEEE 1309. This test procedure applies to ETS-Lindgren/Holaday probes; however, it may be used for similar microwave probes in the frequency range of 2450MHz manufactured by other companies. Calibrations conducted with this procedure will exhibit uncertainties as listed with a confidence of 2 Sigma or 95.5%.
Model
/ / /HI-1501
/TBD
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Doc: 1150-03-3057 Rev: 24 Apr 2014
2. General Responsibility and Authority:
2.1. Calibration Lab Technician must ensure all calibration lab procedures are followed and fully completed. Forward all test information to the Service/Calibration Manager or designee.
2.2. Service/Calibration Manager or designee will ensure all paperwork has been completed, signed and is within tolerances.
2.3. Engineering Representative will provide technical assistance as needed..
3. Equipment Required: Qty:
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Doc: 1150-03-3057 Rev: 24 Apr 2014
H-491218
/Control Box
/1
H-491202
/Microwave Survey Chamber
/1
HI-1501
/Transfer Standard s/n 43111
/1
Fluke-77 or equivalent
/DMM (Digital multi meter)
/1
4. Precautions:
4.1. Handle DUT’s with care to prevent marring or damage.
4.2. Observe all ESD guidelines to prevent electrical damage.
4.3. Customer Units (SRO) refer to section 13. Pre-Calibration Indications
5. Tolerances:
5.1. Devices Under Test (DUT’s), which are considered passing, will indicate within +/- 3% of the calibration set point.
6. Mechanical Zero:
6.1. Set DUT power “OFF”, check that the meter needle is on zero and adjust, as needed using the setscrew in the lower center of meter face housing.
7. Electrical Zero:
7.1. Set DUT selector switch to 2mW, check that the meter needle is on zero and adjust, as needed using the Zero adj. pot on the front panel of the DUT.
8. Bias Setting:
8.1. Connect the DMM common (Black) lead to ground at the battery bracket.
8.2. Set the DMM to read VDC, connect the positive (red) lead to the test point of the white probe wire.
8.3. Adjust regulator trim pot R21 voltage to read between (-.360 to -.390)
8.4. (Note: indications are dependent on the diode array values)
8.5. Connect the positive lead of the DMM to the test point of the black wire. Use R3 to obtain the same voltage indication as the white wire test point.
8.6. Rotate the DUT “ZERO ADJ” knob to the eleven o’clock position. Adjust the balance trim pot R3 to obtain an electrical zero indication on the DUT meter.
8.7. Probe Test.
8.8. Set the DUT selector switch to “Probe Test” and check the meter for a mid scale indication, adjust as needed using R7.
9. Control box setup.
9.1. Turn the control box “ON” (Fig. 3) and allow it to warm for approximately 30 minuets
9.2. Place transfer standard probe in the calibration chamber.
9.3. Set the alignment mark to the straight up position.
9.4. Turn the transfer standard main switch (Fig. 1) to the 2mW/cm2 position and zero the meter.
9.5. Press the control box “RF ON/OFF” button to turn the unit on.
9.6. Adjust the “RF LEVEL” knob until the Transfer standard meter indicates 1mW/cm2.
9.7. Record this reading from the control box display in the station record book as the “IN” indication.
9.8. If the indication is 1mW/cm2 record it in the “OUT” column of the record book.
9.9. If the indicates anything but 1mW.
9.10. Press and hold the “HOLD TO CALIBRATE” button, located on the front of the control box.
9.11. Use the “UP” and “DOWN” buttons to adjust the control box indication to match the transfer standard indication.
9.12. Record control box indication in the station record book in the “OUT” column.
10. Ellipticity Test
10.1. Position the probe in the chamber by placing the gray probe handle into the probe clip on the crossbar.
10.2. Insert the red handle cover into the rotation fixture and tighten the thumbscrew. Place the cable down into the slot of the rotation fixture.
10.3. Assure that the shoulder of the probe head is seated back flush against the probe clip.
10.4. Close the door and set the DUT selector switch to the 2mW scale.
10.5. With RF “OFF” on the Control Box, check DUT Electrical Zero
10.6. Turn the RF “ON” on the Control Box and adjust the RF field level to 1.00 mW with the “RF level” knob. Adjust the 2mW trim pot on the DUT circuit board, so the DUT reads exactly 1.00 mW.
10.7. Rotate the probe slowly thru one complete revolution (360 degrees); it should take about 15 seconds for one revolution. The needle of the DUT meter must not move more than +/- 3% of 1.00mW (.97 to 1.03) indication. If the ellipticity exceeds +/-3%, refer to Appendix 2 for rework instructions.
10.8. Notes For exact readings:
10.9. Rotate the probe to it’s lowest point electrically as indicated by the DUT meter, then adjust the RF field level until the DUT reads exactly 1.00mW. Record the RF field level indicated by the Control Box on the Calibration Worksheet.
10.10. Rotate the probe to it’s highest point electrically as indicated by the DUT meter, then adjust the RF field level until the DUT reads exactly 1.00mW. Record the RF field level indicated by the Control Box on the Calibration Worksheet.
10.11. The difference between the two levels (low and high) is the total ellipticity. Divide by 2 for the +/-% ellipticity. (i.e. 100-95=5, divided by 2 =2.5% ellipticity)
10.12. Rotate the probe to a point midway between the high and low readings as indicated by the DUT meter. Calibrations will be performed at this position.
11. Pre-Calibration Indications: Customer Units (SRO)
NOTE: Precise probe placement and position are essential in achieving accurate and repeatable measurements.
11.1. Turn all test equipment on and allow it to warm up for approximately 30 minutes.
11.2. Visually inspect the DUT for physical damage, defects or battery leakage.
11.3. Check battery strength by setting the DUT selector switch to “Batt. Test”, the meter needle should be above the “Battery OK” line on the meter face. Batteries can also be tested using a DMM, indications should be above 8.5VDC. Change the batteries if the indication is out of the accepted range.
11.4. Check Mechanical Zero
11.5. Position the probe in the chamber.
11.6. Close the door and set the DUT selector switch to the 2mW scale setting.
11.7. With the Control Box RF “OFF”, set DUT Electrical Zero
11.8. Turn the Control Box RF “ON” and adjust the RF power level to indicate exactly 1.00 mW.
11.9. Record the DUT indications on the Calibration Sheet as pre calibration data. The DUT indications must be between .97 and 1.03 to be “In Tolerance”.
12. 2.0mW Range Calibration.
12.1. Set the DUT selector switch to the 2.0mW scale.
12.2. Turn the Control Box RF “ON” and adjust the RF power level to indicate exactly 1.00 mW.
12.3. On the DUT adjust 2mW trim pot R15 to indicate exactly 1.0mW. Record indication in the post calibration column of the worksheet.
12.4. Increase power level to 2.0mW and record DUT indication in post calibration column of the worksheet.
13. 10.0mW range calibration.
13.1. Set the DUT selector switch to the 10mW scale,
13.2. With the Control Box RF “OFF”, set DUT Electrical Zero using the (zero adj.) pot on the front panel of the DUT.
13.3. Turn the Control Box RF “ON” and adjust the RF power level to indicate exactly 5.00 mW.
13.4. Record the DUT indications on the Calibration Sheet in the pre calibration column of the calibration worksheet. The DUT indications must be between 4.85 and 5.15 to be “In Tolerance”.
13.5. Using R14, adjust the DUT to indicate exactly 5.0mW. Record 5.0mW in the post calibration column of the calibration worksheet.
13.6. Adjust power level to 2.0mW, record DUT indications in post calibration column.
13.7. Adjust power level to 1.0mW, record DUT indications in post calibration column.
14. 100.0mW Calibration.
14.1. Set the DUT selector switch to the 100 mW scale.
14.2. With the Control Box RF “OFF”, set DUT Electrical Zero
14.3. Turn the Control Box RF “ON” and adjust RF power level to 5. 00mW.
14.4. Record the DUT indication on the Calibration Sheet. The DUT indications must be between 4.97 and 5.03 to be “In Tolerance”.
14.5. Adjust R13 on the DUT to indicate exactly 5.0mW, record DUT indications in post calibration column.
15. Pre-Calibration Setup: New Units
15.1. Turn all test equipment on and allow it to warm up for approximately 30 minutes.
15.2. Visually inspect the DUT for physical damage, defects or battery leakage.
15.3. Check battery strength by setting the DUT selector switch to “Batt. Test”, the meter needle should be above the green “Battery OK” line on the meter face. Batteries, can also be tested using a DMM, indications should be above 8.5VDC. Change the batteries if they do not meet specifications.
16. Calibration of 2mW range.
16.1. Set the DUT selector switch to the 2mW scale.
16.2. With the Control Box RF “OFF”, set the Electrical Zero on the DUT,
16.3. Turn the Control Box RF “ON” and adjust it to 1.00mW. Adjust the 2mW trim pot R15 (Fig. 2) on the DUT to read exactly 1.00 mW.
16.4. Turn Control Box RF “OFF” and recheck Electrical Zero on the DUT.
16.5. Turn the Control Box RF “ON” and adjust the RF power level until it reads exactly 2.00 mW.
16.6. The DUT reading must be between 1.97 and 2.03.to be “In Tolerance” If it is not, refer to Appendix 2 for rework instructions.
17. 1 mW Linearity check
17.1. Set the DUT selector switch to the 2.0mW scale
17.2. With the Control Box RF “OFF”, set the Electrical Zero on the DUT
17.3. Turn the Control Box RF “ON” and adjust the RF power level to read exactly 1.00 mW
17.4. Match the DUT indication with the control box power level indication.
17.5. Increase the control box power level to indicate exactly 2.0mW.
17.6. The DUT Should indicate between 1.96 and 2.04mW, to be in tolerance.
17.7. Turn the Control Box RF “OFF”.
18. DUT Reaction Time Check.
18.1. Set DUT selector switch to the 2.0mW scale. Set the Fast / Slow toggle switch to the Slow setting. Turn Control Box RF “ON” and measure the time required for the needle of the DUT to reach 90% (.90 mW). Record elapsed time for both the fast and slow switch positions on the Calibration worksheet.
19. Calibration of 10mW range
19.1. Set the DUT selector switch to the 10mW scale.
19.2. With the Control Box RF “OFF”, set the Electrical Zero on the DUT
19.3. Turn the Control Box RF “ON” and adjust the RF power level to read exactly 5.00 mW.
19.4. Adjust the 10mW trim pot R14 so that the DUT reads exactly 5.00mW. Record the DUT reading on the Calibration Worksheet.
19.5. Turn the Control Box RF “OFF” and recheck the Electrical Zero of the DUT.
19.5.1.1. Turn the control box RF on.
19.6. Decrease the power level to indicate 2.0 mW.
19.7. Read DUT indication and record it on the calibration worksheet.
19.8. Decrease the power level to indicate 1.0 mW.
19.9. Read DUT indication and record it on the calibration worksheet.
20. Calibration of 100mW range
20.1. Set the DUT selector switch to the 100 mW scale.
20.2. With the Control Box RF “OFF”, check Electrical Zero on the DUT.
20.3. Turn the Control Box RF “ON” and adjust the RF power level to 5.00mW.
20.4. Adjust the 100mW trim pot R13 so that the DUT reads exactly 5.00mW (first small mark above zero).
20.5. Turn the Control Box RF “OFF”. Set the DUT selector switch to “OFF”.
20.6. Seal all trim pots with red glyptal and place the unit back in the case.
20.7. Fill out the calibration label and place it on the bottom of the can.
21. Printing Data:
21.1. Enter the data in the microwave database.
22. Calibration Complete:
22.1. Upon completion of work/calibration requirements, the lab will generate a Certificate of Calibration. These records will be combined with the data and provided to the customer.
22.2. Units failing calibration will be processed under the guidelines of the Quality Management System.
23. Records:
23.1. Calibration data for equipment (SRO & Production) will be retained no less than five years.
24. Revision History:
See document properties - server
Appendix 1
Ellipticity Rework Instructions
1. Position the probe in the chamber.
2. Ensure that the shoulder of the probe head is seated back flush against the probe clip.
3. Close the chamber door and set the DUT selector switch to the 2mW scale.
4. With the Control Box RF “OFF”, set DUT Electrical Zero
5. Turn the Control Box RF “ON” and adjust the RF field level to 1.00 mW with the “RF level” knob. Adjust the 2mW trim pot on the circuit board of the DUT, so the needle reads exactly 1.00 mW.
6. With the RF field level at 1mW, rotate the probe until you reach a high point.
7. Turn the Control Box RF “OFF”, keeping the DUT in the chamber at the high point position.
8. Open the chamber door, remove the cone from the probe and mark the probe at the top.
9. Remove the probe from the chamber, slide the red grip back and remove the pins from the handle to allow access to the diode array.
10. Lightly file the antenna that is marked, and also the one directly opposite.
11. Reassemble the probe with only one pin, wait a few minutes for the temperature of the diode array to stabilize and recheck ellipticity.