When Do Personal RF Monitors Need Recertification?
The use of RF personal monitors is widespread among wireless tower climbers and technicians. This is a relatively new development of the last five years or so. Prior to that, only a few monitors were in use. These were typically models developed for use by engineers, with a host of features not needed for routine climber protection. Consequently, they were expensive and not frequently used. As safety managers have begun to require all personnel working on wireless facilities to have personal monitors among their personal protective equipment, a new generation of cost effective equipment has emerged.
Many safety managers are concerned about personal training, PPE, and testing and validation of critical safety equipment, including personal RF monitors. That raises the questions “When do monitors need recertificaton?” and “Who can perform recertifications?”
When do monitors need recertificaton?
Most manufacturers recommend a functional calibration or recertification every two years. This is computed from the date of first use (customer delivery) or from the date of the calibration certificate included in the original purchase if delivery records do not exist. LBA keeps a serial number record of each monitor that it sells and its shipment date. LBA customers can check their shipment-based recalibration date by contacting LBA, if it is not posted on the monitor.
LBA agrees with this advice, but cautions that an annual check may be desirable for instruments frequently used outdoors and in a construction or climbing environment. In any event, a function test by the user is advised prior to each day’s work.
There is no practical way to validate RF performance in the field. However, if the function test is abnormal, or the RF monitor alarms are inconsistent with those of nearby units worn by coworkers, then the unit should be submitted for recertification.
Who can perform recertifications?
The services of a specially equipped laboratory are required to verify that operation of a personal RF monitor is within the manufacturer’s specifications. Because the occupational MPE’s monitored represent high levels of RF power, this circumstance must be duplicated in the lab. Each recertification requires a high power amplifier, specially calibrated antenna, a monitor positioning device, and a shielded enclosure – an unusual and pricey set of equipment. Lab personnel must also be familiar with personal RF monitors and have access to manufacturer’s data.
LBA maintains a lab facility suitable to test SafeOne® and fieldSENSE ProHD™ monitors, and the recently introduced fieldSENSE 2.0 as it’s calibration intervals come due in the future. Monitor tests are supervised by iNARTE-certified EMC engineers. LBA believes its facility to be the only one specifically dedicated to these monitors. Other labs having suitable equipment, but not regularly testing these monitors, may be expected to charge several times LBA’s rates for one-off setups.
What is included in an LBA recertification?
Each submitted monitor is given a physical exam for general condition. If in physically good shape, the batteries are replaced and the monitor is cycled through its functions, and their performance validated. Successfully passing this performance check, the RF monitor is positioned in a test fixture in the RF test chamber. Calibrated RF fields are applied to the monitor at four different orientations, and conformance within the manufacturer’s requirements for that condition is verified.
On successful completion of the recertification sequence, a date sticker is applied, a pass-fail record of tests is completed, and the monitor and documentation are returned to the submitter ready to be placed back in service.
If the monitor fails to pass at any point, or if problems are found that would suggest end-of-life, the submitter is notified with options. As a practical matter, repairs may be expected to be a significant part of the cost of a new monitor, and are not recommended. Usually, the best action is to authorize shipment of a new replacement monitor. Because of the safety hazard presented, known defective monitors should never be returned to service, and should be destroyed to avoid inadvertent use.
It is our policy to extend a 50% rebate on test charges for failed units when a replacement unit is purchased form LBA.
What does recertification cost?
LBA charges $155.00 per monitor, which includes return surface shipping in the US. Turnaround time at LBA is normally five business days. A discount is available for bulk quantity submittals, and flexible scheduling is available to minimize impact on customer operations.
For assistance on personal monitor calibration, or to purchase new monitors, contact Michael Senn at firstname.lastname@example.org or 252-757-0279.