- indicating thermometer
- industrial packing
- indicating range
- inductosyn
- inherent delay
- index thermometer
- infrared scanner
- initial verification
- instrument rack
- inspection lid
- integral control
- integrating flowmeter
- integrating wattmeter
- intelligent controller
- integral compensation
- input element
- inspection cap
- inspection cover
- inspection lot
- instability
- instantaneous display
- instruction code
- integral action
- integral network
- integrating vattmeter
- interval length
- interval timing
- inverse problem
- isothermal calorimeter
- jitter
- joint distribution
- Kalman filter
- kilogram
- kilometer
- katathermometer
- ladder diagram
- land surveying
- land surveyor
- large calorie
- laser anemometer
- lead module
- learning control
- length gage
- lead compensation
- length bar
- length metrology
- levellman
- length gauge
- level book
- level gage
- level gauge
- level measurement
- level switch
- leveling compass
- levelling compass
- lifting vehicle
- ligging device
- limit comparison
- limit detection
- limit indicator
- limiting control
- linear interpolation
- linear system
- linear thermometer
- linearization
- liquid manometer
- liquid compass
- load cell
- locating spigot
- look box
- loop control
- loop gain
- loop transmittance
- locator
- Lorentz gage
- Lorentz gauge
- loss measurement
- long measure
- Luenberger observer
- luminance measurement
- luminous dial
- luxmeter
- M contour
- machine load
- magnetic compass
- magnetic thermometer
- main network
- magnetic counter
- manhole cover
- manometric thermometer
- Mahler calorimeter
- major graduation
- measured temperature
- measured value
- measurement reactor
- measurement signal
- measurer
- mass flow
- mass flowmeter
- mechanical manometer