Technical Bulletin

 Leviton supplies dual pyrometers to generate the best PIR detection possible in a 180° FOV, with a

maximum coverage area of approximately 2100 square feet. PIR as a line-of-sight technology has a

maximum sensing distance in front of the sensor of 40 feet, with a 60 foot span (30 feet on each side

of the sensor). PIR technology is optimal when the following is considered: Heat + Size of Heat

Movement + Time Delay = Lights ON. In other words, larger, heated movement within a lengthened

time delay will increase the probability of PIR sensing motion.

Leviton Advantage: Leviton EXCLUSIVE dual PIR elements are a key design advantage that provides twice

the fine motion detection zones and a larger field of view through a small lens height. Other manufacturers use

larger thinner lenses that are inherently prone to damage or tampering, or may offer “vandal resistant” lenses

that have poorer range and sensitivity due to the excessive material thickness. Leviton’s unique design of Dual

PIR elements, small lens height, reinforced internal cage, and a durable lens material provide a combination of

features maximizing a vandal resistance sensor without compromising performance. All Leviton commercial

wall switch sensors employ this vandal resistant design.

Occupancy Sensors Switch Ultra-Sonic (U/S) FOV

 Leviton uses a pair of U/S transducers to actively detect Doppler shifts (compressed reflective waves)

caused by motion in a space. U/S is more sensitive to small movements since it does not rely on

movement between zones or line-of-sight, instead U/S provides complete active coverage of an entire

space. Sensitivity is field configurable for best performance in various spaces.

Leviton Advantage: Active U/S technology was chosen by the leading manufacturers in both occupancy and

security detector markets for the most reliable and efficient way to eliminate false OFFs. Active technology also

allows equipped multi-technology products to be put into single technology mode and operate as U/S only,

disabling PIR for areas where the entry point is not in line of sight. Whereas ultrasonic and PIR technologies

can be used independently, audio technologies must be used with one of the above technologies due to it’s

inherent unreliability for energy savings over time. Audio technologies will keep lights on during vacancy if

sound is detected for any reason. Conversation in hallways or adjacent offices, radios or ambient office noise

can falsely maintain lights in vacant spaces, negatively impacting energy savings and ROI.

Example: The OSSMT occupancy wall box sensor with multi-technology (PIR & U/S).

Coverage Pattern

Coverage patterns are determined by a variety of factors. For PIR, line of sight, lens and segment masking

impact FOV and coverage patterns. For U/S, the direction in which the transmitter and receiver are pointed and

the reflectivity of surfaces in the room will impact sensitivity and coverage for the space. When both

technologies are active as in a multi-technology sensor, the coverage pattern is generally calculated from the

PIR FOV. This is because in multi-technology operation, PIR turns the light ON and the U/S keeps it ON.

Leviton Advantage: Patented FOV blinders are standard in all wall switch sensor models instead of masking

tape. Additionally, Leviton provides a Harmonic Ring on the wall and ceiling mount sensors which allows the

installers to make micro adjustments to the sensor head for fine-tuning the coverage area.

Occupancy Sensor - Operation

This section covers the operational elements of: Multi-technology, Flashing LED status, Sensitivity Adjustment,

Functional Variables, Application Considerations, and Walk Testing for PIR Sensors.

Multi-Technology Operation

PIR is used to detect motion and turn lights on, while either technology is used to keep lights on while the

space is occupied depending on model and adjustments. This scheme permits the U/S to eliminate false OFF