Density Transmitters



Functional Description

  • Accuracy ±0.0004 g/cm³ (±0.1 °Brix);
  • Temperature compensation;
  • Range 0 g/cm³ - 10 g/cm³;
  • Standard industrial and sanitary process connection;
  • Digital LCD indicator;
  • Direct density or concentration readout in engineering units such as g/cm³, kg/m3, Specific Gravity, °Brix, °Baume, °Plato, °INPM, °GL, °API, % Solids, % Concentration, etc;
  • Suitable for dynamic and static liquids;
  • Two wire loop powered;
  • Several different wetted materials;
  • Single integrated unit without moving parts;
  • Factory calibration and Self calibration;
  • In field re-calibration:
    • No standard reference required;
    • No lab calibration required;
    • No process shutdown.
  • Continuous/Self diagnostics;
  • Weather proof, explosion proof and intrinsically safe;
  • The control strategy is built from direct instantiation and deletion of function blocks;
  • Configuration and Parameterization all through open and interoperable configuration tools available in the market, e.g., based on PC or PCMCIA Cards or operations by the local adjustment switches (should be used with a LCD display);
  • Use of the Analog Input function;
  • Totally digital; including sensor, electronics and communication;
  • Configurable Local Adjustment (Foundation fieldbusTM and PROFIBUS PA);
  • Easy firmware upgrade (via Flash Memory Interface) for Foundation fieldbusTM and PROFIBUS PA;
  • Easy maintenance;
  • Three technology options: HART®, Foundation fieldbusTM, PROFIBUS PA.

DT301 - HART® - 4 a 20 mA

  • Multi-drop operation mode;
  • Supports DTM and EDDL.


DT302 - Foundation fieldbus™

  • 17 different types of function blocks for control strategies and advanced diagnostics;
  • Up to 20 function blocks;
  • Two analog inputs: density and concentration or temperature;
  • Execution of up to 31 external links (19 Publisher and 12 Subscriber);
  • 12 mA consumption;
  • Dynamic block instantiation improves interchangeability;
  • Foundation fieldbusTM registered and ITK approved;
  • MVC (Multivariable Container) enabled.


  • 12mA consumption;
  • Three Function blocks for analog inputs: density, concentration and temperature;
  • Integrated to Simatic PDM;
  • Supports DTM and EDDL;
  • Profile 3.0 improves interchangeability.

The DT300 Series Intelligent Density Transmitter is an instrument developed for the continuous, online measurement of liquid density and concentration, directly in the industrial process.

Its pioneer technology consists of a capacitive type differential pressure sensor coupled to a pair of pressure repeaters immersed in the process. A temperature sensor located between the two pressure repeaters is used to compensate the temperature variations in the process fluid.

A dedicated software, by means of an algorithm, calculates the fluid density.

Depending on the industrial process, density may be expressed in g/cm3, Kg/m3, lb/ft3, Specific Gravity, Brix degree, Gay-Lussac degree, Baumé degree, Plato degree, INPM degree, API degree, Solids %, Concentration %, etc.

Designed for process control applications, these 2-wire transmitters generate a signal proportional to the concentration/density. Digital communication for remote calibration and monitoring is also provided.

Block Diagram

The DT300 Series is available in two models:

  • DT300I (Industrial Model) for general purpose;
  • DT300S (Sanitary Model) for food and other applications where sanitary connections are required.

Both models have two mounting types: top mounting (straight type) and side mounting (curved type).

Installation may be done either in open or pressurized tanks, or directly in pipes since the DT300 is suitable for dynamic and static fluids.

The Sanitary model that meet 3-A Certification (Authorization N° 1399) uses a Tri-Clamp connection to allow a quick and easy connection and disconnection from the process. The wetted surface finish is polished and then is free of crevices where food or bacteria can be collected. 3A is the most widely accepted sanitary standard in the food, drug and beverage industry.


DT300 Series - Density Transmitter


  • Sugar and Alcohol Processing Plants: Brix of the sugarcane juice, brix of the must, brix of the syrup, brix of the molasses, brix of the solved juice, calcium solution of the Baumé, interface level of the hexane cycle, lime density, INPM degree of the hydrated alcohol, INPM degree of the anhydrid alcohol, etc.
  • Dairy Product Industries: Condensed milk, Lactose, Yogurt, Cream cheeses, Lactic Acids, etc.  
  • Food Industry: Vegetable oils, miscellaneous extractions, fruit syrup, starch dilution, glucose, jams, jellies, sweets, honey, tomato pulp, citrus juices, etc.  
  • Pulp and Paper Industries: Black liquor, green liquor, white liquor, red liquor, caustic soda concentration, ash dilution, talc dilution, pulp dilution, ink concentration, potassium hydroxide, etc.
  • Beverage Industry: Beer (Plato degree in the fermentation process) Soft Drinks (brix of the liquid sugar, etc.), liquors, wines, soluble coffee, malt, tequila, etc.  
  • Chemical Industry: Acids, concentration/mixture, caustic soda, glycol, salt solution, detergent, toluene, urea, potassium, etc.
  • Mining Slurries: Mineral pulp, extraction of thins, flotation, thickening, acid concentration, starch dilution, scrapers, lime mud.  
  • Petrochemical Industry: Gas washing water, lubricant oils, aromatic extraction, fuel oils, gasoline, kerosene, water/oil interface level.

DT300 Series are available in three different technologies: HART® (DT301), Foundation fieldbusTM (DT302) and PROFIBUS PA (DT303). These instruments can be configured with Smar software and other manufacturers’ configuration tools.

Local adjustment is available in DT302 and DT303. For these models is possible to configure concentration adjust, self-calibration, direct density or concentration readout in engineering units and other control functions using the magnetic screwdriver. Smar has developed Asset View, which is a user-friendly Web Tool that can be accessed anywhere and anytime using an Internet browser. It is designed for management and diagnostics of field devices to ensure reactive, preventive, predictive and proactive maintenance.

DT301 (HART® protocol) can be configured by:
  • HI331 BLUETOOTH for android devices (App DEVCODROID) and Windows PC;
  • Other manufacturers' configuration tools based on DD (Device Description) or DTM (Device Type Manager).




DT302 utilizes the Foundation fieldbusTM H1 protocol, an open technology that allows any H1 enabled configuration tool to configure this device.
Syscon302 (System Configuration Tool) is a software tool used to configure, maintain and operate the field devices. Syscon offers efficient and friendly interaction with the user, using Windows NT version 4.0 or later, Windows 2000 and Windows XP.

Configuration tools such as AMSTM and HHT375 can configure DT302 devices. DD (Device Description) and CF (Capability File) files can be downloaded at either the Smar or Fieldbus Foundation website.
DT302 supports complex strategies configurations due to the high capacity and variety of dynamic instantiable function blocks.

Seventeen different types of function blocks are supported, and up to 20 function blocks can be running simultaneously. Maintenance procedures with Asset View diagnostics and status information from Foundation fieldbusTM result in a safer plant with longer availability.


DT303 (PROFIBUS PA protocol) can be configured using Simatic PDM and by the FDT (Field Device Tool) and DTM (Device Type Manager) concept tools, such as FieldCareTM and PACTwareTM. It can also be integrated by any PROFIBUS System using the GSD file.

PROFIBUS PA also has quality and diagnostic information, improving plant management and maintenance.


Functional Specifications

Output and Communication Protocol
HART®: Two-wire, 4-20 mA with super-imposed digital communication (HART® Protocol).
Foundation fieldbusTM e PROFIBUS PA: Digital only. Complies with IEC 61158-2:2000 (H1): 31.25 kbit/s voltage mode, bus powered.
Power Supply/Current Consumption
HART®: 12-45 Vdc.
Foundation fieldbusTM e PROFIBUS PA: Bus powered: 9 to 32 Vdc. Quiescent current consumption: 12 mA.
4½-digit numerical and 5-character alphanumerical LCD indicator (optional).
Hazardous Area Certifications
HART®, Foundation fieldbusTM e PROFIBUS PA: Explosion proof, weather proof, intrinsically safe, CEPEL, Dekra/EXAM, FM, NEMKO and NEPSI.
Foundation fieldbusTM e PROFIBUS PA: FISCO Ex ia IIC T4 (CEPEL, Dekra/EXAM, NEPSI) and FNICO Ex nl IIC T4 (CEPEL, Dekra/EXAM)
Other Certification
HART®, Foundation fieldbusTM e PROFIBUS PA:3A Sanitary Standard.
Zero and Span Adjustments
Noninteractive, via digital communication or local adjustment.
Failure Alarm (Diagnostics)
Detailed diagnostics through communication for all protocols.
HART®:In case of sensor or circuit failure, the self diagnostics drives the output to 3.6 or 21.0 mA, according to the user’s choice.
Foundation fieldbusTM: For sensor circuit failures, events are generated and status is sent to link outputs. Detailed diagnostics are available in the contained parameters.
PROFIBUS PA: For sensor or circuit failures, status is sent to output parameters. Detailed diagnostics are available in the contained parameters.
Temperature Limits
Ambient: -40 to 85 °C (-40 to 185 °F)
Process: -20 to 150 °C (-04 to 302 °F)
Storage: -40 to 100 °C (-40 to 212 °F)
Digital Display: -10 to 60 °C (14 to 140 °F)
Turn-on Time
HART®: Performs within specifications in less than 5 seconds after power is applied to the transmitter.
Foundation fieldbusTM e PROFIBUS PA: Performs within specifications in less than 10 seconds after power is applied to the transmitter.
HART®: By digital communication (HART® protocol) using the configuration software CONF401, DDCON (for windows), HPC301 or HPC401 (for Palms). It can also be configured using DD and FDT/DTM tools.
Foundation fieldbusTM e PROFIBUS PA: Basic configuration may be done using the local adjustment magnetic tool if device is fitted with display. Complete configuration is possible using configuration tools.
Static Pressure Limit
7 MPa (70 kgf/cm²) (1015 psi).
Humidity Limits
0 to 100% RH.
Damping Adjustment
0 to 32 seconds in addition to intrinsic sensor response time (0.2 s) via digital communication.


Performance Specifications:

Electrical Connection
1/2 - 14 NPT
M20 X 1.5
PG 13.5 DIN
Process Connection Industrial Model: 316 SST Flange ANSI B16.5 4”.
Sanitary Model: 304 SST Tri-clamp 4”.
Wetted Parts Isolating Diaphragms:
316L SST or Hastelloy C276.
Wetted O-Rings (For Sanitary Model):
Buna N, Viton™ or Teflon™.
Nonwetted Parts Electronic Housing:
Injected aluminum with polyester painting or 316 SST. Complies with NEMA 4X, IP66/68 W.
Fill Fluid:
Silicone (DC200/20, DC704), Glycerin and Water, Neobee M20 Propylene Glycol.
Cover O-Rings:
Buna N.
Identification Plate:
Aço Inox 316.
Mounting Side or top mounted.
Approximate Weights 8 kg (18 lb) – Sanitary Model.
13 kg (26 lb) – Industrial Model.


Physical Specifications

Reference Conditions
Temperature of 25 °C (77 °F), atmospheric pressure, power supply of 24 Vdc, silicone oil fill fluid, isolating diaphragms in 316L SST and digital trim equal to lower and upper range values.
Accuracy For range 1: ±0,0004 g/cm³ (±0,1 °Bx)
For range 2: ±0,0007 g/cm³
Linearity, hysteresis and repeatability effects are included.
Stability (for 12 months) For range 1: 0,021 x 10-³ g/cm³
For range 2: 0,083 x 10-³ g/cm³
Ambient Temperature Effect (per 10 °C) For range 1: 0,003 x 10-³ g/cm³
For range 2: 0,013 x 10-³ g/cm³
Static Pressure Effect Pressão Estática no ZeroZero Static Pressure
For range 1: 0,001 x 10-³ g/cm³
For range 2: 0,004 x 10-³ g/cm³
Power Supply Effect ± 0.005% of calibrated span per volt..
Mounting Position Effect It can be eliminated after installation. No span effect.
Electro-Magnetic Interference Effect Designed to comply with IEC 61326-1, IEC 61326-2-3, IEC 61000-6-4 e IEC 61000-6-2.


Dimensional Drawings


Industrial Model


Sanitary Model


SST Tubular Rod                                                                     Hose Rod

Submersible Model


  • Viton and Teflon are trademarks of E. I. DuPont de Nemours & Co.
  • HART® is a trademark of HART® Communication Foundation.
  • Foundation is a trademark of Fieldbus Foundation.
  • Profibus is a trademark of Profibus International.
  • This product is protected by US patent numbers 6,234,019 and D439,855.


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