Installation steps for Rosemount 644 temperature transmitter with threaded sensor

The Rosemount 644 temperature transmitter is a highly cost-effective model in the Rosemount temperature transmitter series. It features a variety of functions and can use HART®, FOUNDATION™ fieldbus, or PROFIBUS® protocols, with options for top, field, or rail mounting styles and various enclosure options. By adding a Local Operator Interface (LOI), the transmitter configuration can be updated on-site without tools. This transmitter also includes diagnostic features such as Hot Backup™, sensor drift warnings, and thermocouple performance degradation to meet different application needs. Today, let's discuss the installation steps for the two different types of Rosemount 644 temperature transmitters with threaded sensors!
　　1. Installation steps for the head-mounted transmitter with threaded sensor!
1. Install the thermowell onto the wall of the pipeline or process container. The thermowell should be installed and tightened before applying process pressure.
2. Connect the necessary extension fittings and adapters to the thermowell. Use silicone tape to seal the threads of the fittings and adapters.
3. Screw the sensor into the thermowell. If required due to harsh environmental conditions or to meet specifications, a vent seal can be installed.
4. Confirm that the transmitter fault mode switch is in the desired position.
5. To verify that the integrated surge protection of the Rosemount 644 device (option code T1) is correctly installed, ensure the following steps have been completed:
a. Ensure the surge protection unit is securely connected to the transmitter's disk assembly.
b. Ensure the surge protector's power leads are securely fastened under the transmitter's power terminal screws.
c. Verify that the surge protector's ground wire is secured to the internal ground screw within the junction box.
6. Pass the sensor leads through the junction box and into the transmitter. Screw the transmitter mounting screws into the mounting holes of the junction box to secure the transmitter.
7. Seal the adapter threads with thread sealant.
8. Pass the field leads through the conduit into the junction box. Connect the sensor leads and power wires to the transmitter. Avoid contact with other terminals.
9. Install and tighten the cover of the junction box. The cover must be fully sealed to meet explosion-proof requirements.

A. Rosemount 644 Transmitter
B. Junction Box
C. Threaded Sensor
D. Extension Fitting
E. Threaded Thermowell
　　2. Installation steps for the field-mounted transmitter with threaded sensor!
1. Install the thermowell onto the wall of the pipeline or process container. The thermowell should be installed and tightened before applying process pressure.
2. Connect the necessary extension fittings and adapters to the thermowell.
3. Use silicone tape to seal the threads of the fittings and adapters.
4. Screw the sensor into the thermowell. If required due to harsh environmental conditions or to meet specifications, a vent seal can be installed.
5. Confirm that the transmitter fault mode switch is in the desired position.
6. Install the transmitter-sensor assembly into the thermowell, which can be installed separately if needed.
7. Seal the adapter threads with silicone tape.
8. Pass the field leads through the conduit into the field-mounted enclosure. Connect the sensor leads and power wires to the transmitter. Avoid contact with other terminals.
9. Install and tighten the covers of the two chambers. The covers must be fully sealed to meet explosion-proof requirements.

A. Rosemount 644 Field-Mounted Type
B. Field-Mounted Enclosure
C. Threaded Sensor
D. Extension Fitting
E. Threaded Thermowell