Compliance with MPE, or Maximum Permissible Exposure to RF levels (as defined in FCC Part 1, OET Bulletin 65) for “controlled” environments, are averaged over _______ minutes, while “uncontrolled” RF environments are averaged over ______ minutes.

6, 30.

"Controlled" environment exists where people are fully aware of the transmissions, while "uncontrolled" one exists for the random population which comes within a proximity of the transmissions, while being unaware of the activity and safety issues regarding the electromagnetic radiation.

For comprehensive info, please see Federal Communications Commission, OET Bulletin 65, Office of Engineering & Technology, pdf called Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields

---

Please see Code of Federal Regulations, Title 10 Chapter III Part 835 Subpart J, - Radiation Safety Training, § 835.901 Radiation safety training.

The overall regulations in this area are on Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 1 Subpart I § 1.1307 - Actions that may have a significant environmental effect, for which Environmental Assessments (EAs) must be prepared.

Also, more specific info is in the same section as above, but § 1.1310 Radiofrequency radiation exposure limits.

---

For great info and links to more resources, see CPWR site for pdf called 5. Regulations & Guidelines for RF Radiation

For a comprehensive info and all Federal Regulations radio communications reference links, please see the Federal Register site article Human Exposure to Radiofrequency Electromagnetic Fields and Reassessment of FCC Radiofrequency Exposure Limits and Policies

Last edited by markadlerdallas. Register to edit

Tags: none

Sites having multiple transmitting antennas must include antennas with more than _______% of the maximum permissible power density exposure limit when evaluating RF site exposure.

5

The aggregate exposure has to be considered when determining whether there is a maximum allowed density exposure. So, any antenna that increases the maximum exposure by 5% has to be included.

For a comprehensive info and all Federal Regulations radio communications reference links, please see the Federal Register site article Human Exposure to Radiofrequency Electromagnetic Fields and Reassessment of FCC Radiofrequency Exposure Limits and Policies

Last edited by markadlerdallas. Register to edit

Tags: none

RF exposure from portable radio transceivers may be harmful to the eyes because:

RF heating may cause cataracts.

Living tissue, such as humans, is affected by radiation from transreceivers. The eyes are probably the most sensitive to RF heating, but the rest of the body also, though to a lesser degrees, depending on the body part.

For example, a key safety rule is to never ever never hold an antenna during transmissions. Those who did often report that it heals much slower than a simple touching of something hot.

Good reference is on the National Library of Medicine site, article
Ocular effects of radiofrequency energy

Additional information on UK Health Protection Agency, pdf document titled Health Effects of Radiofrequency Electromagnetic Fields.

And, Uppsala Universitet pdf titled Damage mechanisms for nearinfrared radiation induced cataract

Last edited by markadlerdallas. Register to edit

Tags: none

At what aggregate power level is an MPE (Maximum Permissible Exposure) study required?

1000 Watts ERP

When transmitting at 1,000 Watts ERP, you are required to perform a maximum permissible exposure study.

Mnemonic: The only choice of Kilo=1000, is the 1000 Watts.

For comprehensive info, please see Federal Communications Commission, OET Bulletin 65, SUPPLEMENT B, Office of Engineering & Technology, pdf called Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields

Also, see OET Bulletin 65, Office of Engineering & Technology, pdf calledEvaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields.

---

From: wp2ahg
Memory aid: At a kilowatt, will it kilo-you?

Last edited by markadlerdallas. Register to edit

Tags: none

Why must you never look directly into a fiber optic cable?

An active fiber signal may burn the retina and infra-red light cannot be seen.

Since fiber optic cables transmit light of various frequencies, including those human eyes don't see, you never know if the fiber optic cable is transmitting. Thus, never look directly into a fiber optic cable.

Overall good review can be found on The Fiber Optics Association site, article
Safety in Fiber Optic Installations

The FOA pdf on Safety Rules for Fiber Optics provide a good list of safety procedures.

A good discussion of dangers can be found on the Electrical Contractor site, article
Myths of Fiber Optics

Last edited by markadlerdallas. Register to edit

Tags: none

If the MPE (Maximum Permissible Exposure) power is present, how often must the personnel accessing the affected area be trained and certified?

Yearly.

All the employees who come in a proximity to powerful transmissions have to attend training and get certified.

Please see Code of Federal Regulations, Title 10 Chapter III Part 835 Subpart J, - Radiation Safety Training, § 835.901 Radiation safety training.

The overall regulations in this area are on Code of Federal Regulations, Title 47 Chapter I Subchapter A Part 1 Subpart I § 1.1307 - Actions that may have a significant environmental effect, for which Environmental Assessments (EAs) must be prepared.

Also, more specific info is in the same section as above, but § 1.1310 Radiofrequency radiation exposure limits.

---

For comprehensive info, please see Federal Communications Commission Office of Engineering & Technology, pdf called Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields

For great info and links to more resources, see CPWR site for pdf called 5. Regulations & Guidelines for RF Radiation

Last edited by markadlerdallas. Register to edit

Tags: none