【Useful Tips】Installation Steps for the Rosemount 644 Temperature Transmitter with Threaded Sensor

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　　The Rosemount 644 temperature transmitter is a highly cost-effective model in Rosemount’s range of temperature transmitters. It has diverse functions, can use HART® or FOUNDATION™ fieldbus protocols as well as PROFIBUS® protocol, and is available in top-mounted, field-mounted, or rail-mounted styles along with various enclosure options. By adding a Local Operator Interface (LOI), the transmitter configuration can be updated on-site without the need for tools. The transmitter also includes diagnostic functions such as Hot Backup™, sensor drift warnings, and thermocouple performance degradation to meet various application requirements. Today, we will discuss the installation steps for the two different types of Rosemount Temperature Transmitter Model 644 with threaded sensors! 　　I. Installation steps for head-mounted transmitters with threaded sensors! 　　1. Install the heat sleeve on the wall of the pipe or process vessel. Before applying process pressure, the heat sleeve should be installed and tightened. 　　2. Connect the necessary extension nozzles and adapters to the heat sleeve. Seal the nozzle and adapter threads with silicone tape. 　　3. Screw the sensor into the heat sleeve. Emission seals can be installed for reasons related to harsh environments or to meet regulatory requirements. 　　4. Confirm that the transmitter fault mode switch is in the desired position. 　　5. To verify that the integrated transient protection (option code T1) for the Rosemount 644 device has been installed correctly, please ensure that the following steps have been completed: a. Ensure that the transient protector unit is firmly connected to the transmitter disc assembly. 　　b. Ensure that the power lead of the transient protector is securely fixed under the screw of the transmitter’s power terminal. 　　c. Verify that the grounding wire of the transient protector is secured to the internal grounding screw in the universal junction box. 　　6. Pass the sensor leads into the universal junction box and the transmitter. Insert the transmitter mounting screws into the mounting holes of the universal junction box, thereby installing the transmitter in the universal junction box. 　　7. Seal the adapter threads with thread sealant. 　　8. Pass the field leads through the conduit into the universal junction box. Connect the sensor leads and power cable to the transmitter. Avoid contact with other terminals. 　　9. Install and tighten the universal connector cover. The shell covers must be tightly fitted together to meet the explosion-proof requirements. 　　A. Rosemount 644 transmitter B. Universal junction box C. Threaded sensor D. Extension piece E. Threaded heat sleeve Installation steps for field-mounted transmitters with threaded sensors! 　　1. Install the heat sleeve on the wall of the pipe or process vessel. Before applying process pressure, the heat sleeve should be installed and tightened. 　　2. Connect the necessary extension nozzles and adapters to the heat sleeve. 　　3. Seal the nozzle and adapter threads with silicone tape. 　　4. Screw the sensor into the heat sleeve. Emission seals can be installed for reasons related to harsh environments or to meet regulatory requirements. 　　5. Confirm that the transmitter fault mode switch is in the desired position. 　　6. Install the transmitter-sensor assembly in the heat sleeve; it can be installed separately if necessary. 　　7. Seal the adapter threads with silicone tape. 　　8. Pass the field leads through the conduit into the field installation enclosure. Connect the sensor leads and power cable to the transmitter. Avoid contact with other terminals. 　　9. Install and tighten the covers for the two chambers. The shell covers must be tightly fitted together to meet the explosion-proof requirements. 　　A. Rosemount 644 field-mounted type B. Field mounting enclosure C. Threaded sensor D. Extension piece E. Threaded heat shield