SAES-T-492 PDF – VHF/UHF Land-Mobile and Fixed Radio Communication

This article is about SAES-T-492 which is about VHF/UHF Land-Mobile and Fixed Radio Communication and download SAES-T-492 PDF for telecommunication and electrical engineers, supervisors and project managers, telecom QCs, telecom QC Supervisors. This is saudi aramco standards of Telecommunication Engineering based on international codes and standards and useful for telecom and electronics engineering knowledge to get job as engineers, QC Supervisors and QC managers, Engineering managers and technicians.

SAES-T-492 PDF Download

SAES-T-492

VHF/UHF Land-Mobile and Fixed Radio Communication

SAES-T-492 is a Saudi Aramco Engineering Standard that establishes the minimum mandatory requirements for the engineering of VHF/UHF mobile and fixed radio telecommunications systems. The purpose of this standard is to promote compatibility between existing and future equipment. The standard covers a range of components including transmitters, receivers, portable/personal transceivers, and antennas for both base stations and vehicles. By adhering to these requirements, Saudi Aramco ensures efficient and effective communication systems that meet the company’s needs.

Design:

5.1 Compliance with Importation Requirements:

All radio equipment mentioned in this standard must conform to the government’s requirements for the importation of radio telecommunication equipment into the Kingdom. The specific procedures for radio equipment importation can be found in the following Material Instructions (MIs) and General Instructions (GIs):

• MI-321.015: Materials Requiring Saudi Arab Government Import Permits, Letters of Authorization, and/or Clearance Permits
• MI-321.021: Import Permits for Communications Equipment
• GI-1603.000: Importation of Communications Equipment

5.2 Area Classification:

VHF/UHF radio systems operated in classified areas must adhere to the guidelines outlined in SAES-B-068 and be certified by Factory Mutual Research Corp. (FM) or any other association listed in paragraph 8.2 of SAES-P-100, “Basic Power System Design Criteria.” The area classification requirements are as follows:

• For Class 1, Division 1 areas: Gas Groups C&D (Ethylene & Propane)
• For Class 1, Division 2 areas: Gas Groups A, B, C & D (Acetylene, Hydrogen, Ethylene & Propane)
• Alternatively, for Class 1, Zone 1 areas: Gas Groups IIb (Ethylene & Propane)
• Alternatively, for Class 1, Zone 2 areas: Gas Groups IIc (Acetylene, Hydrogen, Ethylene & Propane)

Additionally, the battery of the handheld radio must be capable of carrying the load for a minimum of 8 hours. The minimum battery capacity can be calculated using the standard duty cycle of 10-10-80%, as described by the formula:
A = (ITX * 10% + IRX * 10% + IS * 80%) * 8
where A is the required battery capacity for 8 hours (mA-H), ITX is the transmit current (mA), IRX is the receive current (mA), and IS is the standby current (mA). The transmit, receive, and standby currents are provided by the manufacturer.

5.4 Communications Antennas:

5.4.1 Base Station Antennas:
The minimum standard for base station antennas is per EIA/TIA 329-C.

5.4.2 Vehicular Antennas:
The minimum standard for vehicular antennas is per EIA/TIA 329-C.

Commentary Note:
For Radio Frequency Dispatch units (Desktop Radios), the antenna requirements can be derived from the vehicular antennas requirement, as the Radio Frequency Dispatch unit can be treated as a special case of vehicular antenna requirements.

When VHF/UHF radio is used for SCADA (Supervisory Control and Data Acquisition) communications, it must adhere to the requirements specified in SAES-Z-004.

Testing and Inspection:

Testing and Inspection:

Field testing and inspection of the radio equipment must be conducted, and the results should be recorded in a logbook. The logbook should be handed over to the Proponent Department. The field tests should include, at a minimum, the following requirements:

7.1 Inspecting Connections:
Inspect the solid connections of wires and grounds to ensure safety and proper operation of the radio equipment.

7.2 Operating Frequencies:
Verify the operating frequencies of transmitters and receivers to ensure they are set correctly.

7.3 RF Power and Coverage Area:
Verify the RF power output of transmitters and confirm the coverage area of the base station to ensure it meets the desired requirements.

7.4 RF Cable and Antenna Matching:
Check the matching between RF cables and antennas to ensure proper signal transmission and minimize reflection. Verify the Voltage Standing Wave Ratio (VSWR) to assess the quality of the match.

7.5 Signal-to-Noise Ratio (SINAD):
Check the Signal-to-Noise Ratio (SINAD) for receiver systems to assess the quality of the received signal and the level of noise interference.

These field tests and inspections help ensure the proper functioning and performance of the radio equipment, and the results should be documented for reference and future maintenance purposes.

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