Smart Temperature Transmitter

TTC        SMART TEMPERATURE TRANSMITTER      LAB #X

                                                YOKOGAWA YT200

OBJECTIVES

1.         Introduce the Yokogawa YT200 Smart Temperature Transmitter and BT200 Brain Terminal functions and operations.

2.         Calculate and validate smart temperature transmitter output responses.

3.         Perform a 4-20 mA trim (i.e. "D to A" calibration).

4.         Calibrate the input section (i.e. "A to D" calibration).

THEORY

Smart transmitters are microprocessor based instruments intended for applications requiring improved accuracy and remote transmitter communication.  These applications incorporate transmitters installed in inaccessible locations and transmitters requiring frequent range or calibration changes. 

Smart field communicators are hand held interfaces that permit communication with the smart transmitters.  Communication includes both sending and receiving data from the transmitter over a communication link.  This link is actually the 4-20 mA signal wiring on which a digital signal is superimposed.  The communication link to the transmitter can take place at the transmitter, from the control room, or from any wiring termination point in the measurement loop.

EQUIPMENT

- Yokogawa YT200 Smart Temperature Transmitter            - 250 Ohm Resistor

- Yokogawa BT200 Brain Terminal                                           - 24 Volt Power Supply

- Fluke 8060A DMM                                                                      - Type J Thermocouple

- 100  PT100D RTD                                                                     - Temperature Baths

- Micromite II Calibrator

PRE-LAB

1.         Explain the difference between a smart temperature transmitter and a conventional analog temperature transmitter.

2.         Explain what is meant by “configuring” a smart temperature transmitter versus "calibrating" a smart temperature transmitter.

PROCEDURE

1.         Make a proper ice bath.   Set the temperature baths for 50°C and 80°C. Having exactly the right temperature (baths) is not necessary.

2.         Connect the Yokogawa YT200 Smart Temperature Transmitter to the bench 24 volt power supply.  Include in the loop a 250 ohm resistor (necessary for digital communication), Fluke DMM, and the BT200 Brain Terminal.  Note that the BT200 can be connected at any termination point in the signal loop.  Refer to the drawing shown below:

3.         First turn on the 24 volt power supply for the transmitter, then turn on the BT200 Brain Terminal by pressing the [ON/OFF] key.  The brain terminal runs through a self-test, then comes up in the initial data panel.  From the initial data panel, you can access the main menu panel by pressing the [F4] key.  Please see pages 4-6 to 4-12 of the BT200 Brain Terminal manual for the basic operations of the terminal.   

            To become familiar with moving around the menu structure of the 275, follow the procedure as outlined on pages 4-6 to 4-13 of the BT200 Brain Terminal manual, “BASIC OPERATIONS”.  Note that these pages are for connection to a pressure transmitter, but the menus for the temperature transmitter are quite similar.

4.         Configure the YT200 Smart Temperature Transmitter for the following:

            Input Type                           =          type J thermocouple

            Unit                                        =          C

            Lower Range Value            =          0C

            Upper Range Value            =          80C

            Damping Time                     =          1 second

            Display Select                      =          user set

            RJC setting                          =          on

           

          Note, all of the above changes to the configuration are "output-related information" elements.  The communication block diagram and parameter summary are the only references provided by the manufacturer, these are on pages 23 to 26 of the YT200 manual.

          Note, don't bother changing the non-output related information at this time... these elements do not directly affect the transmitter output, so we will ignore this information for the time being!

5.            Quickly verify the configuration by measuring the temperature of each bath with a thermometer and the YT200 Temperature Transmitter. Record all required information in table 1. (Note, reference temperature measurement is the glass thermometer ... don't forget about the correction factor!)

5.         (continued)

           

            Note, it is possible to display the temperature and transmitter output (as measured by the transmitter) on the brain terminal display.  Go to the main menu panel, then select option A, “DISPLAY”.  Temperature and transmitter output are updated once every 6 seconds.

            Note, for table 1, temperature is to be calculated based on the mA signal as measured and indicated by the DMM.

6.         It is possible to set the transmitter to fail up or down via software configuration.  Refer to the block diagram and parameter summary on pages 24 to 26 of the YT200 manual, then configure the transmitter for  upscale burnout.  To verify upscale burnout, simulate thermocouple burnout by disconnecting one of the thermocouple wires from the transmitter, then observe the transmitter output signal as indicated by the DMM.  Record your observations

7.         Configure the transmitter for  downscale burnout.  To verify downscale burnout, simulate thermocouple burnout by disconnecting one of the thermocouple wires from the transmitter, then observe the transmitter output signal as indicated by the DMM.  Record your observations           

           

8.         Disconnect the thermocouple from the transmitter, then connect a 3-wire, 100 ohm ice point platinum RTD (European alpha) to the transmitter.  Follow the directions given on page 20 of the YT200 manual.

9.         Configure the 3044C Smart Temperature Transmitter for a 3-wire RTD.  Other information as follows:

            Input Type                           =          100 ohm ice point platinum RTD,

                                                                        European alpha, 3-wire

            Unit                                        =          C

            Lower Range Value            =          0C

            Upper Range Value            =          100C

            Damping Time                     =          1.0 seconds

            Display Select                      =          user set

                     

            Refer to the directions given in step 4.  

10        Quickly verify the configuration by measuring the temperature of each bath with a thermometer and the YT200 Temperature Transmitter. Record all required information in table 2. (Note, reference temperature measurement is the glass thermometer ... don't forget about the correction factor!)

            Note, for table 2, temperature is to be calculated based on the mA signal as measured and indicated by the DMM.

11.       Please note again that it is possible to set the transmitter to fail up or down via software configuration.  Refer to the block diagram and parameter summary on pages 24 to 26 of the YT200 manual, then configure the transmitter for  upscale burnout.  To verify upscale burnout, simulate RTD burnout by disconnecting the RTD wires from the transmitter, then observe the transmitter output signal as indicated by the DMM.  Record your observations  

12.       Configure the transmitter for  downscale burnout.  To verify downscale burnout, simulate RTD burnout by disconnecting the RTD wires from the transmitter, then observe the transmitter output signal as indicated by the DMM.  Record your observations

           

13.       With Yokogawa Smart Transmitters, it is possible to perform a 4-20 mA trim (i.e. "digital trim", D/A converter).  If this procedure is to be performed, it is important that the transmitter output be measured with a very accurate ammeter.  We will use the Fluke 8060A to measure the current output ... however, a more accurate meter should be used!

            Prior to performing this calibration, record the current as indicated by the Fluke at 4 mA, 8 mA, 12 mA, 16 mA and 20 mA.   Record your observations in table 3.  Perform this test by going to the main menu panel, then select option K, “TEST”, then select k10, “OUTPUT %”.    Again, refer to the communication block diagram and parameter summary on pages 23 to 26 of the YT200 manual.

            To do a digital trim, go to the main menu panel, then select option C, “ADJUST”, then select C10 AND C11, “OUTPUT 4mA” and “OUTPUT 20mA”.    Again, refer to the communication block diagram and parameter summary on pages 23 to 26 of the YT200 manual.

13.       (continued)

            After performing the digital trim, record the current as indicated by the Fluke at 4 mA, 8 mA, 12 mA, 16 mA and 20 mA.  Record your observations in table 3. Perform this test by going to the main menu panel, then select option K, “TEST”, then select k10, “OUTPUT %”.    Again, refer to the communication block diagram and parameter summary on pages 23 to 26 of the YT200 manual.

14.       With Yokogawa Smart Transmitters, it is also possible to calibrate the input section of the transmitter (i.e. "sensor trim", A/D converter).  If this procedure is to be performed, it is important that the transmitter input be simulated with a very accurate device.  In this step, we will use the Micromite II to simulate an RTD input ... however, a more accurate device should be used!

           

            Disconnect the 3-wire RTD from the transmitter, then connect the Micromite II to the transmitter (make the Micromite II look like a 3-wire RTD).

            Prior to performing the sensor trim, ensure that the transmitter is still configured for a temperature range of 0C to 100C, then record the temperature as indicated by the brain terminal (go to the main menu panel, then select option A, “DISPLAY”) when simulating temperatures of 0C, 25C, 50C, 75C and 100C (use RTD table to determine the resistance values that correspond to these temperatures).  Record your observations in table 4.

            To do the sensor trim, go to the main menu panel, then select option C, “ADJUST”, then select C20 AND C21, “ZERO ADJ” and “SPAN ADJ”.    Again, refer to the communication block diagram and parameter summary on pages 23 to 26 of the YT200 manual.

After performing the sensor trim, record the temperature as indicated by the brain terminal (go to the main menu panel, then select option A, “DISPLAY”) when simulating temperatures of 0C, 25C, 50C, 75C and 100C (use RTD table to determine the resistance values that correspond to these temperatures).  Record your observations in table 4.

15.       Now that you have performed a 4-20 mA trim and a sensor trim, repeat step 11. Record all required information in table 5.  You should find that you now have less error due to the "trims".

          Note, again, temperature is to be calculated based on the mA signal as measured and indicated by the DMM.

           

TTC                                       RESULTS                                      LAB #X

NAME:          _______________________________              DATE: __________________

LAB PARTNER:     _____________________________      CLASS: _________________

Pre-Lab

Signature:    ________________________

Difference between a smart temperature transmitter and a conventional analog temperature transmitter (pre-lab Q#1):

What is meant by "configuring" versus "calibrating" (pre-lab Q#2):

           
Completion of table 1 (step 5):

           

Temp Source	Uncorrected Thermometer Reading (°C)	True Source Temp. (°C)	Measured Loop Current (DMM, mA)	Smart Tx Temp. (°C)	Error   (°C)
Ice bath
50C bath
80C bath

                                                          Table 1

Note, for table 1, temperature is to be calculated based on the mA signal as measured and indicated by the DMM.

Observation of transmitter output (step 6):

Observation of transmitter output (step 7):

Completion of table 2 (step 10):

Temp Source	Uncorrected Thermometer Reading (°C)	True Source Temp. (°C)	Measured Loop Current (DMM, mA)	Smart Tx Temp.  (°C)	Error   (°C)
Ice bath
50C bath
80C bath

                                                          Table 2

Note, for table 2, temperature is to be calculated based on the mA signal as measured and indicated by the DMM.

Observation of transmitter output (step 11):

Observation of transmitter output (step 12):

"D to A" calibration (step 13):

Before			After
Output Setting (%)	Expected Current (mA)	Actual Current (mA)	Output Setting (%)	Expected Current (mA)	Actual Current (mA)
0	4		0	4
25	8		25	8
50	12		50	12
75	16		75	16
100	20		100	20

                                                          Table 3

"A to D" calibration (step 14):

Before			After
Simulated Input Setting (°C)	Expected Temp. Display (°C)	Actual Temp. Display (°C)	Simulated Input Setting (°C)	Expected Temp. Display (°C)	Actual Temp. Display (°C)
0	0		0	0
25	25		25	25
50	50		50	50
75	75		75	75
100	100		100	100

                                                          Table 4

Completion of table 5 (step 15):

Temp Source	Uncorrected Thermometer Reading (°C)	True Source Temp. (°C)	Measured Loop Current (DMM, mA)	Smart Tx Temp.  (°C)	Error   (°C)
Ice bath
50C bath
80C bath

                                                          Table 5

Note, for table 5, temperature is to be calculated based on the mA signal as measured and indicated by the DMM.

   

Reference NAIT Edmonton CA