Rosemount 644 Датчик температуры

The Rosemount 644 temperature transmitter is ideal for critical applications (in many types of process environments). It provides reliability with advanced accuracy for all installations. The Rosemount 644 can be ordered with either 4–20 mA/HART or a completely digital FOUNDATION fieldbus protocol. Each unit can be configured for a variety of sensor inputs: RTD, thermocouple, millivolt, or ohm. DIGITAL FIELD DEVICES THAT POWER PLANTWEB The advanced 644 powers PlantWeb® by communicating important temperature diagnostics and PlantWeb alerts to ensure process health and enable economical single-sensor architecture. TRANSMITTER-SENSOR MATCHING Entering the temperature-resistance profile specific to the RTD sensor into the 644 transmitter results in transmitter-sensor matching. This eliminates the sensor interchangeability error, which can improve accuracy by up to 75%. INTEGRAL LCD DISPLAY Local indication of temperature measurement and diagnostics provides immediate and accurate verification of process conditions. RELIABLE TRANSMITTER PERFORMANCE Meeting the NAMUR NE 21 recommendations, the 644 ensures top transmitter performance in harsh EMC environments. In addition, the 644 HART transmitter meets NAMUR NE 43 and NE 89 recommendations. MOUNTING FLEXIBILITY DIN A style head mount transmitters fits a variety of housings for remote transmitter mounting and can be integral or remote mounted to a sensor. The compact rail mount style is great for DIN rail mounting in the tight spaces of a crowded control room. Rosemount Temperature Solutions Rosemount 644 Temperature Transmitter Head mount styles available with HART or FOUNDATION fieldbus protocol. Rail mount style available for HART protocol. Rosemount 848T Eight Input Temperature Transmitter Eight input transmitter available with FOUNDATION fieldbus protocol. Rosemount 3420Fieldbus Interface Module Provides an interface between FOUNDATION fieldbus instruments and systems without fieldbus capability using standard interface protocols. Rosemount 248 Temperature Transmitter Head mount style (DIN B) and Rail mount style with HART protocol and complete temperature assembly. Rosemount 148 Temperature Transmitter Head mount style (DIN B) PC-programmable transmitter. Rosemount sensors, thermowells, and extensions Rosemount has a broad offering of RTD and thermocouples that are designed to meet plant requirements. HART AND FOUNDATION FIELDBUS Functional Specifications Inputs User-selectable; sensor terminals rated to 42.4 V dc. See “Accuracy” on page 7 for sensor options. Output Single 2-wire device with either 4–20 mA/HART, linear with temperature or input; or a completely digital output with FOUNDATION fieldbus communication (ITK 4.5 compliant). Isolation Input/output isolation tested to 500 V ac rms (707 V dc) at 50/60 Hz Local Display The optional five-digit integral LCD Display includes a floating or fixed decimal point. It can also display engineering units (°F, °C, °R, K, Ω, and millivolts), milliampere, and percent of span. The display can be configured to alternate between selected display options. Display settings are preconfigured at the factory according to the standard transmitter configuration. They can be reconfigured in the field using either HART or FOUNDATION fieldbus communications. Humidity Limits 0–99% relative humidity Update Time ≤ 0.5 seconds Accuracy (default configuration) PT 100 HART (0-100 °C): ±0.18 °C FOUNDATION Fieldbus: ±0.15 °C FOUNDATION FIELDBUS SPECIFICATIONS Function Blocks Resource Block • The resource block contains physical transmitter information including available memory, manufacture identification, device type, software tag, and unique identification. Transducer Block • The transducer block contains the actual temperature measurement data, including sensor 1 and terminal temperature. It includes information about sensor type and configuration, engineering units, linearization, reranging, damping, temperature correction, and diagnostics. LCD Block • The LCD block is used to configure the local display, if a LCD Display is being used. Analog Input (AI) • Processes the measurement and makes it available on the fieldbus segment • Allows filtering, alarming, and engineering unit changes. PID Block • The transmitter provides control functionality with one PID function block in the transmitter. The PID block can be used to perform single loop, cascade, or feedforward control in the field. Turn-on Time Performance within specifications in less than 20 seconds after power is applied, when damping value is set to 0 seconds. Status If self-diagnostics detect a sensor burnout or a transmitter failure, the status of the measurement will be updated accordingly. Status may also send the PID output to a safe value. Power Supply Powered over FOUNDATION Fieldbus with standard fieldbus power supplies. The transmitter operates between 9.0 and 32.0 VDC, 11 mA maximum. The power terminals are rated to 42.4 VDC (max.). Alarms The AI function block allows the user to configure the alarms to HI-HI, HI, LO, or LO-LO with a variety of priority levels and hysteresis settings. Backup Link Active Scheduler (LAS) The transmitter is classified as a device link master, which means it can function as a Link Active Scheduler (LAS) if the current link master device fails or is removed from the segment. The host or other configuration tool is used to download the schedule for the application to the link master device. In the absence of a primary link master, the transmitter will claim the LAS and provide permanent control for the H1 segment. Hardware and Software Failure Mode The 644 features software driven alarm diagnostics and an independent circuit which is designed to provide backup alarm output if the microprocessor software fails. The alarm direction (HI/LO) is user-selectable using the failure mode switch. If failure occurs, the position of the switch determines the direction in which the output is driven (HI or LO). The switch feeds into the digital-to-analog (D/A) converter, which drives the proper alarm output even if the microprocessor fails. The values at which the transmitter software drives its output in failure mode depends on whether it is configured to standard, custom, or NAMUR-compliant (NAMUR recommendation NE 43, June 1997) operation. Table 1 shows the configuration alarm ranges. Custom Alarm and Saturation Level Custom factory configuration of alarm and saturation level is available with option code C1 for valid values. These values can also be configured in the field using a HART Communicator. Turn-on Time Performance within specifications in less than 5.0 seconds after power is applied, when damping value is set to 0 seconds. Transient Protection The Rosemount 470 prevents damage from transients induced by lightning, welding, or heavy electrical equipment. For more information, refer to the 470 Product Data Sheet (document number 00813-0100-4191).