Current through Register Vol. 54, No. 50, December 14, 2024
Section 105.15 - Calibration and testing procedure(a)General. An electronic device shall be calibrated and tested as follows:(1)Power output. Relative power output shall be measured in the following manner: (i) Adjust dc power supply to 13.6 vdc.(ii) With equipment still connected as in Appendix A, Figure 2, position (1), position antenna system along each axis for maximum coupling. Simultaneously increase attenuation to avoid overloading the thermister amount.(iii) Adjust microwave variable attenuator for maximum attenuation and then calibrate microwave power meter.(iv) Reduce attenuation until microwave power meter reads 0 dB.(v) Calculate power output taking into consideration the gain of the horn, and attenuation of the microwave variable attenuator, added algebraically with the power level indicated on the power meter. Example:
Attenuator | 33.6 dB |
Power Meter Reading | 0.0 dB |
______ |
33.6 dB |
Gain of Horn | -16.7 dB |
Relative Power | ______ |
16.9 dB | = 48.98. |
(2)Transmitted frequency. Transmitted frequency shall be measured in the following manner: (i) Adjust variable dc power supply to 13.6 vdc.(ii) With the equipment connected as in Appendix A, Figure 2, position (2) adjust the microwave variable attenuator for a stable readout on frequency counter.(iii) Record transmitter frequency as indicated on the microwave frequency counter. Frequency shall be within .2% of licensed frequency.(iv) Vary the applied voltage from 11 vdc to 14 vdc. Frequency shall remain within .2% of licensed frequency.(3)Stability test. The stability test shall be conducted in the following manner:(i) Adjust variable dc power supply to 13.6 vdc.(ii) Connect equipment as in Appendix A, Figure 2, position (3).(iii) Adjust square wave output of function generator to the switching level of the pin diode switch. While observing the frequency counter, adjust frequency of function generator to 1726 Hz (X-Band) or 3961 Hz (K-Band) or 5692 Hz (Ka-Band).(iv) Vary applied dc voltage from 11 vdc to 14 vdc while observing indicated speed on device being tested. Indicated speed may not vary.(4)Relative sensitivity. Relative sensitivity shall be measured in the following manner:(i) Adjust variable dc power supply to 13.6 vdc.(ii) Connect equipment as in Appendix A, Figure 2, position (3).(iii) Adjust range control if applicable on electronic device for maximum range.(iv) Adjust square wave output of function generator, to switching level of pin diode modulator. While observing frequency counter, adjust frequency of function generator so that device being tested indicates 55 mph.(v) Slowly increase attenuation of microwave variable attenuator, until speed reading of 55 mph of device being tested becomes erratic.(vi) Readjust position of device for maximum coupling.(vii) Repeat steps in subparagraphs (v) and (vi) until no further increase is possible, without losing display. Maximum coupling is imperative.(viii) Calculate relative sensitivity of device being tested, taking into consideration attenuation or gain of each component in the microwave path. The reflected signal passes through devices two times therefore values shall be multiplied by two. Example:
| Gain of Horn | 16.7 dB x 2 | +33.4 dB |
| Attenuation | 33 dB x 2 | -66 dB |
| Relative Sensitivity | -32.6 dB |
(5)Accuracy test. The accuracy test shall be conducted in the following manner: (i) Adjust variable dc power supply to 13.6 vdc.(ii) Connect equipment as in Appendix A, Figure 2, position (3).(iii) Adjust square wave output of function generator, to switching level of pin diode modulator. While observing frequency counter, adjust function generator for an indicated speed of 55 mph.(iv) Adjust microwave variable attenuator and range control for stable display.(v) While observing the frequency counter, adjust the function generator to each test frequency. Note and record the speed indicated on the electronic device display. Each test frequency shall produce the correct speed in mph within the limits of +0, -1 mph. Test Frequencies (in Hz)
| X Band | K Band | Ka Band | Indicated Test Speed mph |
| 628 | 1440 | 2070 | 20 |
| 785 | 1801 | 2588 | 25 |
| 942 | 2161 | 3105 | 30 |
| 1099 | 2521 | 3622 | 35 |
| 1256 | 2881 | 4140 | 40 |
| 1412 | 3241 | 4657 | 45 |
| 1569 | 3601 | 5175 | 50 |
| 1726 | 3961 | 5692 | 55 |
| 1883 | 4321 | 6210 | 60 |
| 2040 | 4681 | 6727 | 65 |
| 2197 | 5042 | 7246 | 70 |
| 2354 | 5402 | 7762 | 75 |
| 2511 | 5762 | 8281 | 80 |
| 2668 | 6122 | 8797 | 85 |
| 2825 | 6482 | 9316 | 90 |
| 2982 | 6842 | 9832 | 95 |
| 3139 | 7202 | 10351 | 100 |
| 3296 | 7562 | 10867 | 105 |
| 3453 | 7922 | 11385 | 110 |
| 3610 | 8283 | 11902 | 115 |
| 3767 | 8643 | 12420 | 120 |
| 3924 | 9003 | 12937 | 125 |
| 4081 | 9363 | 13455 | 130 |
| 4238 | 9723 | 13972 | 135 |
| 4394 | 10083 | 14490 | 140 |
(6)Tuning fork test. The tuning fork test shall be conducted in the following manner: (i) Connect the microphone, ac voltmeter and frequency counter as depicted in Appendix A, Figure 2.(ii) Strike the tuning fork on a block of wood and hold the vibrating tuning fork close to the microphone.(iii) Adjust the gain of the audio amplifier for a stable display on the frequency counter.(iv) Note the displayed frequency on the frequency counter and convert it into miles per hour. The calculated speed shall be the same as that indicated on the tuning fork or within 1%. The tuning fork shall be at room temperature, or approximately 70° F., when this measurement is taken.(v) Strike the tuning fork on a block of wood and hold it close to the device antenna. The indicated speed shall be stable, and shall be that of the tuning fork.(7)Rejection of extraneous RF fields.(i) Adjust variable dc power supply to 13.6 vdc.(ii) Position the base loaded antenna 1 meter from the radar assembly.(iii) Activate the 4 watt signal source, modulated at 100%, 1726 Hz (X-Band) or 3961 Hz (K-Band) or 5692 Hz (Ka-Band).(iv) There may be no readout on the electronic device indicator, related to the extraneous RF field.(b)Maintenance work-order. A maintenance work-order containing the following information shall be completed and forwarded to the Communications Division:(1) Serial number of the electronic device.(2) Work performed and date of same.(3) Original complaint, if any.(4) Actual repairs performed, if any.(5) Amount of time taken to repair unit.(6) Manufacturer's stock number of all equipment replaced.(8) Individual part prices for all equipment replaced.(9) The name and address, class, serial number and expiration date of the operator's license of the individual conducting the test. The testing individual shall also sign and date the maintenance work order. Maintenance performed shall conform with FCC rules and regulations pertaining to radio location devices.(c)Certificates of accuracy. These forms, provided by the Department, shall be filed for each electronic device calibrated and tested. (1) Original shall be filed at the State Police station.(2) One duplicate copy shall be retained by the maintenance and calibration station for at least 2 years.(3) One duplicate copy shall be forwarded to the Communications Division, State Police.(4) One duplicate copy shall accompany the electronic device.(5) A duplicate copy, executed and signed in the same manner as the original, has the same force and effect as the original.(d)Electronic device-radar-calibration. Technical data forms provided by the State Police Communications Division, shall be filed for each electronic device calibrated and tested.(1) One original shall be forwarded to the Communications Division, State Police.(2) One duplicate copy shall be retained by the maintenance and calibration station for at least 2 years.(3) A duplicate copy, executed and signed in the same manner as the original, has the same force and effect as the original.The provisions of this § 105.15 adopted August 26, 1977, effective 8/27/1977, 7 Pa.B. 2422; corrected September 2, 1977, effective 8/27/1977, 7 Pa.B. 2564; amended August 18, 1978, effective 8/19/1978, 8 Pa.B. 2310; amended August 18, 1978, effective 8/19/1978, 8 Pa.B. 2310; republished and compiled August 1, 1980, effective 8/2/1980, 10 Pa.B. 3199; amended January 15, 1982, effective 1/16/1982, 12 Pa.B. 299; amended June 18, 1982, effective 6/19/1982, 12 Pa.B. 1875; corrected June 29, 1984, effective 1/16/1982, 14 Pa.B. 2267; readopted December 4, 1987, effective 12/5/1987, 17 Pa.B. 5051; amended February 17, 1989, effective 2/18/1989, 19 Pa.B. 640; amended July 31, 1998, effective 8/1/1998, 28 Pa.B. 3588. This section cited in 67 Pa. Code § 105a.4 (relating to system and speed timing device use and certification).