Tel-Tru Digi-Tel Temperature Transmitter Instructions

Operating Instructions for Digi-Tel Temperature Transmitter (DTTT)

Designed for use with Tel-Tru Digi-Tel interchangeable probes and display modules. Use with Tel-Tru Pt1000 O probe assemblies. Ideal for variable process environments—not necessary to have a separate probe and transmitter for different ranges. One transmitter—many ranges. Use with or without Tel-Tru Digi-Tel Display Modules.


CONTENTS
Connect Digi-Tel Probe to DTTT Connect Digi-Tel Display to DTTT Range Chart Connect to Power Supply DTTT Calibration and Range Selection Procedure Set Up to Calibrate	mA Calibration Mode Temperature Calibration Mode Return to Operation Incomplete Calibration Procedure Temperature Range Selection Local Setup 4 to 20 mA Scaling Options	Use of RTD Simulators with Digi-Tel Display Modules Confirm Accuracy of Digi-Tel Thermometer Display Modules

Connect Digi-Tel probe to DTTT Select probe options: Probe lengths match bimetal thermometer standard stems with 1/2" NPT connections for use in thermowells with standard .260 bore. Select "P2" for use with ranges up to 750°F (400°C) Select "P3" (with inconol stem) for use with ranges over 750°F (400°C) up to 1200°F (600°) Male connection on probe plugs into female connection on DTTT Tighten fitting to assure hermetic seal DTTT may be used without the display module. When using with probe only use of part number 1043501 is suggested to seal top end of DTTT
		Larger View See Example

Connect Digi-Tel display module to DTTT Select Display module-options: Digi-Tel 3" display modules: Analog/Digital display Factory selected ranges (see Range Chart) Direct or remote mount Digi-Tel 5" display modules: Digital only display Temperature range is full span of the instrument (see Range Chart) Direct mount styles Digi-Tel 4½" display module Digital only display Temperature range is full span of the instrument (see Range Chart) Remote mount style DTTT male connection plugs into female connector of display module Tighten fitting to assure hermetic seal
		Larger View See Example
		Range Chart Larger View
Connect to Power Supply Standard 2 wire Hirschmann type connection Mini DIN 43650C Connect to plant mA loop For units with cables, connect the black wire to mA - and the brown wire to mA+		Fig. 3
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DTTT Calibration and Range Selection Procedure Refer to the calibration setup drawing (Fig. 4) or setup example for all transmitter connections used during the calibration procedure. * Ranges may be selected using the control room read-out (Fig. 5) through the plant loop or in the field (Fig. 6) using a mA loop calibrator.
Larger View See Example	Larger View	Larger View See Example
Set Up to Calibrate Disconnect the probe and display module from the transmitter, if applicable. Note that the display module may remain connected, but it will not display a correct reading during the calibration process. Connect a loop calibrator (Ex. Tel-Tru Model 530) to the + and – mA connections on the transmitter (set to read power measure mode). Remove the screw labeled “Select Range” to access the range selection switch. Move the switch to position 1. Verify that the loop calibrator display reads 5.5 mA for a few seconds to indicate position 1 has been selected. If 5.5 mA is not displayed on the loop calibrator, then rotate the DTTT dipswitch, one position at a time, until it comes to that reading. Rotate the switch clockwise for a higher reading, and counter-clockwise for a lower reading. Short Digi-Tel Temperature Transmitter with a pin jumper by momentarily plugging a paper clip or small wire into both small holes in the transmitter’s probe connector. The loop calibrator display should read greater than 21 mA to indicate the transmitter is now in mA calibration mode. Remove the wire. mA Calibration Mode With the switch remaining in position 1, connect a resistance RTD source simulator for PT1000 (Ex. Tel-Tru Models 510 or 512) to the transmitter’s probe connector. Use of the supplied connector is recommended. Adjust the resistance source until the loop calibrator reads 4.000 mA ± 3 µA. Move the switch one step clockwise to position 2 (loop calibrator display will read 6.5 mA for a few seconds) to calibrate 20 mA. Adjust the resistance source until the loop calibrator reads 20.000 mA ± 3 µA. Temperature Calibration Mode Move the switch one step clockwise to position 3 (read 7.5 mA for a few seconds) to enter temperature calibration mode. Adjust the resistance source to 765.5 ohms (-75ºF). Move the switch one step clockwise to position 4 (read 8.5 mA for a few seconds) to calibrate high temperature. Adjust the resistance source to 3292.9 ohms (1200ºF). Move the switch one step clockwise to position 5 (read 9.5 mA for a few seconds). This is the end of the calibration routine. Return to Operation Disconnect the resistance source and install the probe and display module, if applicable. Install "Select Range" screw. Incomplete Calibration Procedure If it is necessary to stop the procedure once started, disconnect and start from the beginning. If the unit has not been calibrated or calibration process is incomplete, the current reading in position 1 will be 5.5 mA + .25%.

Temperature Range Selection Local Set Up Procedure may be completed with probe only connected or with probe and display connected. Connect a loop calibrator (Ex. Tel-Tru Model 530) to the + and - mA connections on the transmitter. Remove the screw labeled "Select Range" to access the range selection switch. Check the range selection guide for the temperature range desired and the loop calibrator mA reading that represents that range. Rotate selector switch with screw driver to select desired range. Loop calibrator will read mA reading for a few seconds to confirm range selection. Replace screw and install unit into process system. 4 to 20 mA Scaling Options The Digi-Tel digital only display modules (4½" and 5") with broad temperature ranges -75/1200ºF, -60/650ºC, -75/750ºF, or -60/400ºC may be scaled for the full temperature range or for a narrower range. The Digi-Tel Temperature Transmitter can be scaled according to the operating range required. 4-20 mA scale can be changed as needed by using a dip switch position for a more narrow range. See 4 to 20 mA Scaling Options Chart 4 to 20 mA Scaling Options in °F 4 to 20 mA Scaling Options in °C Regardless of the analog scale on the 3" analog/digital range module, the digital scale will work from -75°F (-60°C) to 750°F (400°C). The transmitter range is independent of the display module range. This gives the user complete flexibility in selecting any temperature range for their transmitter, regardless of the range of the attached display module. For this reason even an analog/digital display module with a 25/125°F range could be scaled to a 4 to 20 mA transmitter reading for a 50/550°F range. Also see Range and mA Output Reference Table		Larger View

Use of RTD Simulators with Digi-Tel Display Modules Calibration Process - Display module, if connected to DTTT, will not show a reading during this process. Direct Connection of RTD Simulators to Digi-Tel Display Modules - Will display a temperature reading of 26-30ºF higher than the simulator output signal. Reason: The display is not a passive readout device. The inaccuracy results from a confilict in electronic signal processing between the Pt1000 Simulator output and the rapid sampling of that output by a microprocesor in the display. Direct Connection of RTD Simulators to Digi-Tel Temperature Transmitter - 4 - 20mA output readings are correct, with or without display module conected to DTTT. Readings of display module connected to DTTT will be incorrect, per note above, even though 4 - 20mA reading is correct. To Confirm Accuracy of Digi-Tel Thermometer Display Modules Connect display module to Digi-Tel probe assembly. Place unit into calibration bath or dry block calibrator. Confirm reading. Accuracy of Digi-Tel thermometers is controlled by a microprocessor in the display module that samples and conditions the Pt1000 signal every 3 seconds. The display modules are not designed for field adjustment. Please contact Tel-Tru with any questions regarding calibration or accuracy. For additional guidance on the calibration testing process of Digi-Tel products see: Recommendations for Checking the Calibration of Bimetal Thermometers.