Fundamentals and Units of Measurement 1675polarization beam splitter PBS
polyethylene PE
polyethylene aluminum steel polyethylene PASP
Polypropylene PP
Polyurethane PUR
polyvinyl chloride PVC
polyvinylidene fluoride PVDF
positive-negative-positive PNP
positive, intrinsic, negative PIN
potential acoustic gain PAG
pound lb
pound (force) per square inch. Although the use of
the abbreviation psi is common, it is not recom-
mended.lbf/in^2 , psi,pound-force lbf
pound-force foot lb·fft
poundal pdl
power backoff PBO
power calibration area PCA
power factor PF
power factor correction PFC
power level LW, dB-PWL
power out Po
power over ethernet PoE
power sourcing equipment PSE
power sum alien ELFEXT PSAELFEXT
power sum alien equal level far-end crosstalk PSAELFEXT
Power sum alien far-end crosstalk PSAFEXT
Power sum alien near-end crosstalk PSANEXT
power sum alien NEXT PSANEXT
powered devices PD
preamplifier preamp
precision adaptive subband coding PASC
precision audio link PAL
prefade listen PFL
primary rate interface ISDN PRI
printed circuit PC
private branch exchange PBX
Professional Education and Training Committee PETC
programmable gate array PGA
programmable logic device PLD
programmable read-only memory PROM
public switched telephone network PSTN
pulse code modulation PCM
pulse density modulation PDM
pulse end modulation PEMTable 48-9. Recommended Abbreviations
Unit or Term Symbol or
Abbreviationpulse-amplitude modulation PAM
pulse-duration modulation PDM
pulse-frequency-modulation PFM
pulse-position modulation PPM
pulse-repetition frequency PRF
pulse-repetition rate PRR
pulse-time modulation PTM
pulse-width modulation PWM
quadratic residue diffuser QRD
quality factor Q
quality of service QoS
quandrature amplitude modulation QAM
quart qt
quarter wave plate QWP
quaternary phase shift keying QPSK
rad rd
radian rad
radio data service RDS
radio frequency RF
radio frequency identification RFID
radio information for motorists ARI
radio-frequency interference RFI
rambus DRAM Rambus,
RDRAM
random access memory RAM
random-noise generator RNG
rapid speech transmission index RASTI
reactance X
read only memory ROM
real-time analyzer RTA
real-time transport protocol RTP
Recording Industry Association of America RIAA
recording management area RMA
red, green, blue RGB
redundant array of independent disks RAID
reflection-free zone RFZ
reflections per second RPS
Regional Data Center RDC
registered communication distribution designer RCDD
remote authentication dial-in user service RADIUS
report on comments ROC
report on proposal ROP
request for proposals RFP
resistance-capacitance RC
resistance-inductance-capacitance RLC
resistor RTable 48-9. Recommended Abbreviations
Unit or Term Symbol or
Abbreviation