*A

Here’s a list of Instrumentation abbreviations starting with the letter “A”, commonly used in P&IDs, datasheets, control systems, and field instrumentation.

A: Alarm / Analyzer / Amperes (depends on context)
AA: Alarm Annunciator / Analytical Analyzer
AAC: Automatic Analog Controller
AAD: Analyzer Air Dryer
AAG: Analyzer Air Guard
AAL: Automatic Air Load
AAR: Automatic Analyzer Recorder
AAS: Atomic Absorption Spectroscopy
ABC: Automatic Bypass Controller
ABD: Automatic Backwash Device
ABP: Air Bleed/Bypass Pressure
ABT: Automatic Burner Trip
AC: Alternating Current / Air Compressor
ACA: Air-Cooled Analyzer
ACC: Accessory / Automatic Control Circuit
ACI: Alternating Current Input
ACL: Air-Cooled Liquid
ACM: Air-Control Module
ACS: Automatic Control System
ACT: Air Control Transmitter
ACV: Air-Control Valve
AD: Analyzer / Air Dryer
ADA: Automatic Drip Annunciator
ADC: Analog-to-Digital Converter
ADD: Additional Device/Data
ADF: Automatic Defrost
ADR: Analyzer Data Recorder
ADS: Analyzer Data System
AE: Acoustic Emission
AEI: Acoustic Emission Inspection
AES: Automatic Emission Sensor
AF: Air Filter
AFD: Auto Flow Diverter
AFS: Auto Flush System
AG: Air Gap
AGC: Automatic Gain Control
A/G: Air/Gas
AH: Air Heater / Alarm High
AHD: Air Handler Device
AI: Analog Input / Auto Ignition
AIC: Analog Input Card
AID: Analyzer Interface Device
AIN: Analog Input
AIR: Air
AIT: Analog Input Transmitter
AIX: Analyzer Input/Output
AL: Alarm Low / Air Line
ALC: Automatic Level Controller
ALD: Automatic Logic Device
ALM: Alarm
ALO: Alarm Output
ALS: Alarm System / Alarm Switch
ALT: Altitude / Alternate
AM: Annunciator Module / Air Movement
AMB: Ambient
AMC: Annunciator/Monitoring/Control
AMF: Auto Manual Function
AMP: Ampere / Amplifier
AMT: Analyzer Mount
AN: Analyzer
ANA: Analog
ANC: Analog to Numeric Converter
ANDV: Automatic Non-Return/Directional Valve
ANR: Air to Nitrogen Regulator
ANS: Annunciator Status
AO: Analog Output / Actuator Output
AOC: Analog Output Card
AOD: Air Operated Device
AOV: Air-Operated Valve
AP: Air Purge / Absolute Pressure
APA: Air Purge Assembly
APC: Automatic Pressure Controller
APD: Absolute Pressure Detector
API: American Petroleum Institute
APL: Auto Purge Line
APM: Air Purge Module
APP: Apparatus
AQ: Analyzer Quality
AR: Alarm Reset / Auto Recycle
ARC: Arc-Resistant Controller
ARD: Automatic Recycle/Reset Device
ARM: Alarm/Relay Module
ARS: Auto Reclosing Switch
ART: Alarm Reset/Test
AS: Alarm System / Auto Switch
ASC: Automatic Sequence Controller
ASD: Air Shutdown
ASI: Alarm Status Indicator
ASM: Alarm/Status Module
ASP: Analyzer Sample Probe
ASV: Air Supply Valve
AT: Auto/Analog Transmitter
ATA: Analyzer Test Assembly
ATC: Automatic Temperature Controller
ATD: Auto/Analog Test Device
ATI: Automatic/Analog Transmitter Indicator
ATJ: Air Temperature Junction
A/T: Auto/Timer
ATM: Atmosphere
ATS: Automatic Transfer Switch
AU: Audio / Auxillary
AUX: Auxiliary
AV: Air Valve / Analog Value
AVC: Auto/Analog Valve Controller
AVD: Air/Vacuum Device
AW: Air Washer
AX: Accessory
AZ: Azimuth / Auto Zero