GE Hydran 201 i Instruction Manual page 294

Appendix I • Glossary
protection against corrosion, windblown dust and rain, splashing water, hose directed
water, and damage from external ice formation.
Network: Group of interrelated or interconnected nodes
NO: Normally Open
NPT: National Pipe Thread (United States)
Null Modem: A special connection between two computers that makes them think they are
hooked up to a modem, so that the two computers can communicate with each other
O : Oxygen
2
Oil Sample: Small quantity of oil, representative of the oil contained in the transformer
PC: Personal Computer, a computer typically based on an Intel microprocessor and capable
of receiving network cards, modems, data acquisition boards, etc.
PCB: Printed Circuit Board
PDF: Portable Document Format
PLC: Programmable Logic Controller
P/N: Part Number
POT: POTentiometer
ppm: Part Per Million, representing the concentration of a gas in transformer oil
PVC: PolyVinyl Chloride, a plastic used for cable insulation
PWM: Pulse Width Modulation
RAM: Random Access Memory, a semiconductor-based memory that can be read and
written by the microprocessor or other digital hardware devices
Range: A continuous band of signal values that can be measured or sourced. In bipolar
instruments, the range includes positive and negative values.
I-8 Rev. 6, March 2011 Part 17997