The Smith Meter ATG Automatic Temperature Compensator gives net (temperature-corrected) registration on a PD meter by continuously integrating gross volume and product temperature. It uses no clutches, cams or ratchets, so the output is continuous and non-cyclic, which suits small-volume mechanical displacement provers and instruments that would otherwise hunt. The bulb mounts directly in the meter housing or adaptor for fast response. A thermal system, gravity (coefficient of expansion) selector dial, primary gear train and a roller-and-disc integrator do the correction. The ATG is bidirectional and also provides registration adjustment. Supplied in Standard and LPG versions.
Key specifications
Standard ATG range: 0-110° API, 1.075-0.580 SG at 60/60 °F, coefficient of expansion 0.0003-0.0011/°F
LPG-ATG range: 0.600-0.500 SG, coefficient of expansion 0.0010-0.0025/°F (0.0018-0.0045/°C)
Mechanical correction: 15% total (standard), 30% (LPG); primary gear output 13% (standard) or 31% (LPG) above input
Thermal system: Standard 0 to 150 °F; specials from -50 to 100 °F up to 325 to 525 °F; 100, 150 or 200 °F spans
Ambient temperature: -30 to 130 °F (-35 to 55 °C)
Linearity / hysteresis: ±1 °F per 100 °F; less than 0.25 °F
Time constant: 50 seconds to 2/3 response to a temperature step
Registration adjustment: One turn of adjusting screw = 0.6% (standard) or 1.2% (LPG); clockwise decreases registration
Capillary lengths: 26, 42 or 52 in standard; bellows movement 0.002 in per °F
Mounting: Part of the meter, dual-head adaptor, single-head adaptor or ventilated extension (12 in to 10 ft; use assembly 518866-001 above 200 °F); remote thermal well available
How to specify / order
The bulletin gives assembly numbers rather than a position code. Replacement / standby ATG assemblies:
Coupling (A) - S and T meters, E3-S1 through H8-S1, dual-head adaptor, ventilated extension, set-stop counter or LNC mounting. Standard ATG, 96% input: 516727-001 (42 in), -003 (52 in), -005 (26 in); 100% input: 519141-001 / -003 / -005. LPG-ATG, 96% input: 516727-021 / -023 / -025; 100% input: 519141-021 / -023 / -025
Coupling (B) - W, D and M meters, B-170 through 875, C2-S1 through S7, H8-S3/S5/S6/S7, and (as printed) J10-S1, S3, S5, S6 and S7 through M16-S1, S3 and S5. Standard ATG, 96% input: 516727-002 (42 in), -004 (52 in), -006 (26 in); LPG-ATG, 96% input: 516727-022 / -024 / -026
96% input applies to ATGs on a meter, dual-head adaptor or ventilated extension; 100% input (Series 519141) to ATGs mounted on a set-stop counter, LNC or turbine-meter stepper motor
With a new meter, specify minimum, normal and maximum temperature and the basis of correction (SG or API gravity at 60 °F, API group, or coefficient of expansion); LPG trim meters get the LPG-ATG automatically
For field retrofit, also give the meter model and serial number
Bulletin notes: the standard ATG coefficient range is printed as ".005-.0020/°C" (should read 0.0005); the standard 0 to 150 °F thermal system is printed as -15 to 65 °C (0 °F is about -18 °C); the revision block names bulletin "SS01109" instead of SS01037; "Hysterisis". Assembly numbers above are as printed; confirm interchangeability with the factory.
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 SS01037 Rev 0.3 (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.