The Smith Meter ATC Automatic Temperature Compensator gives net volume or weight registration on a PD meter. A thermal system (bulb, capillary, product bellows and ambient bellows) positions the plunger of an eccentric-type calibrator, so rising temperature reduces registration and falling temperature increases it. The eccentric-arm fulcrum pin is set for the product's coefficient of expansion. The ATC calibrator also serves as the manual meter adjustment. Versions: meter ATC (integral well; external well on T meters), dual-head adapter ATC for both gross and net registration, single-head adapter ATC (adapter kit 519288-001 needed on an LNC), and ventilated extension ATC for liquids above 300 °F (capillary up to 60 in).
Key specifications
Correction range: SG 1.075 to 0.500 at 60/60 °F; coefficient of expansion 0.0003 to 0.0017/°F (0.0005 to 0.003/°C)
Mechanical correction: 8.5% total; dual- and single-head adapter versions have 1% more temperature range than meter ATC
Thermal system: Standard 0 to 150 °F; specials -50 to 100, 50 to 200, 125 to 225, 175 to 275, 175 to 375, 225 to 425, 275 to 475, 325 to 525 °F
Ambient temperature: -30 to 130 °F
Linearity / hysteresis: ±1 °F per 100 °F; less than 1/4 °F
Time constant: 50 seconds to 2/3 response to a temperature step
Meter adjustment: One notch of the adjusting screw = 1 °F temperature change; clockwise decreases registration
Weight registration: Special gearing so one calibrator output revolution equals a chosen weight; consult the factory
Extensions: Dual-head / ventilated extension length 8 in to 10 ft
Ordering information
Per the bulletin, provide:
Temperature: minimum, maximum and average
Basis of correction: API gravity at 60 °F, or SG at 60 °F or 15 °C; coefficient of expansion per °F or °C, or SG at minimum and maximum operating temperature
Base temperature, if other than 60 °F or 15 °C
Special gearing and/or special bulb filling, if required by the temperature-range chart
Mounting: meter ATC, dual-head adapter, single-head adapter or ventilated extension (with extension length or capillary length)
Bulletin notes: the correction range is printed "API Gravities: 0°F to 150°F" (should be degrees API); one special thermal range reads "225 or 425"; the features paragraph says coefficients up to 0.0020/°F and temperatures to 525 °F while the performance table stops at 0.0017/°F; "Hysterisis".
Pricing and lead time are quoted per configuration. Send the model number (or the details above) with your meter model and serial number to Flow Measurement Services for a quote. Specifications summarized from Smith Meter bulletin SS01038 Rev 0.1 (4/18); confirm current data with the factory before ordering.
Smith Meter (formerly FMC Technologies / TechnipFMC Measurement Solutions), now manufactured by Guidant. Flow Measurement Services supplies and services Smith Meter equipment.