Omega TX91 manuale d’uso

FM APPROVED TX91 Thermocouple T wo-Wire T emperature T ransmitter omega.com e-mail: info@omega.com For latest product manuals: omegamanual.info U ser ’ s Guide Shop online at MADE IN[...]

Servicing North America: U.S.A.: ISO 9001 Cer tified One Omega Drive, Box 4047 Stamford, CT 06907-0047 T el: (203) 359-1660 F AX: (203) 359-7700 e-mail: info@omega.com Canada: 976 Bergar Laval (Quebec) H7L 5A1, Canada T el: (514) 856-6928 F AX: (514) 856-6886 e-mail: info@omega.ca For immediate technical or application assistance: U.S.A. and Canada[...]

It is the policy of OMEGA Engineering, Inc. to comply with all worldwide safety and EMC/EMI regulations that apply . OMEGA is co nstantly pur- suing certification of its products to the European New Approach Directives. OMEGA will add the CE mark to every appropriate de vice upon certification. The information contained in this document is believed[...]

TX91 Miniature T wo-Wire Thermocouple T ransmitter Page Section 1 Introduction 1 1.1 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.3 Models A vailable . . . . . . . . . . . . . . . . . . . . . . [...]

TX91 Miniature T wo-Wire Thermocouple T ransmitter Page Section 4 Calibration Instructions 18 4.1 Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.2 Set-up of Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.3 Calibration Procedur es . . . . . . . . . . . . . . . . . . .[...]

1 1 Introduction 1.1 General Description The OMEGA ® TX90 Series T emperatur e T ransmitters consist of the TX91 Miniature T wo-W ire Thermocouple T ransmitter and the TX92 Miniature T wo-W ire R TD T ransmitter . This manual is written for the OMEGA TX91 Thermocouple T ransmitter . The TX91 T ransmitter accepts thermocouple sensor types J, K, T ,[...]

Figure 1-1. Photo of TX90 Series T ransmitter Figure 1-2. General Dimensions (in inches) 1 2 Introduction 1 (For Mounting)[...]

3 1 Introduction The TX91 transmitter is normally powered by an unr egulated DC power supply as shown in Figure 1-3. The pr oportionally-transmit- ted signal begins at 4 mA, at the low end of its temperature range, and increases to 20 mA, at the high end of its temperatur e range. (There ar e various temperature ranges and thermocouple types availa[...]

0 4 Introduction 1 The TX91 two-wire transmitter r eceives and measures signals from thermocouples and sends an output current of 4-20 mA which is directly proportional to the thermocouple millivolt input. It is designed to connect with only two copper wire leads that will supply the voltage to operate the transmitter from a DC power supply , and a[...]

0 5 Introduction 1 The TX91 has reverse supply polarity pr otection and will operate with a wide range of supply voltages (1 1 to 44VDC). It has an input sensor break-pr otection circuit that forces the output curr ent to go upscale when the thermocouple wire opens. It also is pr ovided with a screw terminal, where the output curr ent can be measur[...]

Figure 1-4. S traight line Approximation of Curve 0 6 1 Introduction[...]

1.2 Features • 4-20 mA output • ±0.1% full-scale accuracy (with respect to the mV input signal) • Upscale break pr otection • Low cost 1.3 Models A vailable 1 Introduction 0 7 T able 1-1. Range Code Input T ypes Range J K T E 0 to 1 200°F J2 K2 T2 E2 -4 0 to 1 300°F J3 K3 T3 E3 -4 0 to 1 500°F J4 K4 T4 E4 -4 0 to 1 750°F J5 K5 E5 -4 0 [...]

Model Number Description TX91-(*) Thermocouple transmitter (J, K, T , or E) NB1TX-(*) NB1 thermocouple probe, 12" L, 1 / 4 " O.D., ungrounded junction, 304SS sheath, TX91T ransmitter TX91 Models Available 8 *Insert range code from T able 1-1 For complete information on NB1 Thermocouple Probes, see the OMEGA T emperature Handbook. 1 Introd[...]

9 2 Unpacking Remove the packing list and verify that all equipment has been received. If ther e are any questions about the shipment, please call the OMEGA Customer Service Department at 1-800-622-2378 or (203) 359-1660. Upon receipt of shipment, inspect the container and equipment for signs of damage. T ake particular note of any evidence of r ou[...]

3.1 Mounting the TX91 The TX91 T ransmitter may be: 1. surface mounted, 2. mounted inside a protection head (r efer to figure 3-1), or 3. installed into the OMEGA mounting track (part number RT) using an OMEGA mounting bracket (part number TX90-BR). Figure 3-2 shows the R T mounting track. Figure 3-3 shows the TX90-BR mounting bracket. Figure 3-4 s[...]

3 Installation Figure 3-1 Assembly of the TX91 T ransmitter Inside an OMEGA NB1 Protection Head (in inches) 11 DC PO WER SUPPL Y LO AD MOUNTING HOLES THERMOCOUPLE[...]

Figure 3-2 R T Mounting T rack (in inches) 12 Installation 3 CAUTION HANDTIGHTEN TRANSMITTER MOUNTING SCREWS ONL Y . DO NOT OVER- TIGHTEN.[...]

3 Installation 13 Figure 3-3 TX90-BR Mounting Bracket (in inches)[...]

Figure 3-4 Installation with Bracket and T rack (in inches) TX90-BR & R T 14 Installation 3 MOUNTING TRACK (RT) MOUNTING BRACKET TX90-BR[...]

15 3 Installation NOTE A milliamp monitoring instrument can be used in the circuit by connecting the monitor’ s positive lead to (+PS) and the negative lead to (M). This allows monitoring the current loop without disconnecting the main wiring. 3.2 Wiring the TX91 (Refer to Figure 3-5) 1. Connect a DC power supply in series with the load to the (+[...]

Installation 3 Figure 3-5 W iring Diagram for the TX91 Potentiometers 16 THERMOCOUPLE[...]

17 4 Calibration Instructions 4.1 Equipment Required • Precision mV sour ce, with 0.001 mV resolution and ±0.002mV accuracy or • Precision DVM with ±0.002mV accuracy and adjustable mV source with 0.001mV r esolution • OMEGA TRC III Ice Point Reference (or stable ice bath) • T emperatur e Reference Probe (OMEGA P/N: TRP-(*)) *Thermocouple [...]

18 Calibration Instructions 4 4.2 Set-up of Equipment T o pr epare the ice bath: a) Fill a glass beaker with crushed ice made from distilled water . b) Fill the beaker with enough distilled water so that ice just becomes slush, but not enough to float the ice. c) Insert the refer ence thermocouple. Figure 4-2 shows an alternate set-up. Her e, a hig[...]

19 Calibration Instructions 4 4.3 Calibration Procedures (Refer to Figur e 4-1) Connect the calibration equipment according to Figur e 4-1 or 4-2. The thermocouple wire (J, K, T , E) must be of the same calibration as the transmitter being calibrated. Make sure that the wiring polarities are corr ect. (Note that the RED thermocouple wire is NEGA TI[...]

20 4 Calibration Instructions If a Thermocouple Calibrator/Simulator is used, such as the OMEGA Model CL51 1 Precision Calibrator , select the T emperature Input Z (zero) and S (span) values. 3. Set the DC mV source to the selected Z (zero) mV value. Adjust the Z potentiometer to read 4.000 mA on the monitoring instrument. 4. Set the DC mV source t[...]

Figure 4-1. Calibration Set-Up Calibration Set-up 4 21[...]

Figure 4-2. Calibration Set-Up. (Alternate) 22 Calibration Instructions 4 SP AN TX91 ZERO INPUT THERMOCOUPLE WIRE[...]

4 Calibration Instructions 23 T able 4-1. Calibration Values for the TX92 T emperature mV INPUT Input Range Model REF 32°F Zero/Span TX92 Zero/Span 0/ 1 200°F -J2 -0.855/ 1 4.906 0/ 1 300°F -J3 -0.885/ 1 7.947 0/ 1 500°F -J4 -0.885/14.108 0/ 1 750°F -J5 -0.885/20.406 0/1000°F -J6 -0.885/29.515 0/ 1 200°F -T2 -0.674/ 1 3.967 0/ 1 300°F -T3 -[...]

Malfunction or incorrect operation may be caused by: 1. Reversed polarity: Check the wiring using Figure 3-5 as a guide. If the temperatur e of the thermocouple increases while the curr ent magnitude decreases, the pr oblem could caused by reversed polarity of the: a) thermocouple wiring b) power supply leads c) monitor instrument 2. Loose or broke[...]

25 5 T roubleshooting Guide a) Measure the total r esistance of each device (excluding the transmitter and power supply) in the 20 mA loop, including the resistance of the lead wir es. b) Calculate the maximum allowable loop resistance using the formula: Loop Resistance (maximum) = V supply -1 1V 0.020A For example, a 24V power supply would give a [...]

26 6 Accessories Model No. Description TX90-BR Mounting Bracket PSU-24B Unregulated Power Supply , 24 V olts TX82A Process Loop-Powered Indicator RT 48” Mounting T rack[...]

27 7 Specifications General SIZE: 1.75" dia. X 1.125" high (includes terminal strip) ZERO/SP AN ADJUSTMENT RANGE: ±25% POWER SUPPL Y VOLT AGE OPERA TING RANGE: +11VDC to +44VDC, 28 mA max required per transmitter ACCURACY : ±0.1% of full scale (includes effects of hysteresis, repeatability and linearity proportional to the T/C) AMBIENT [...]

Specifications 7 28 THERMAL ZERO SHIFT : < 0.01%/°F of span (span >5 mV) < 0.02%/°F of span (2-5 mV span) THERMAL SP AN SHIFT : < 0.01%/°F of span WEIGHT : 1.5 oz (50g) Output CURRENT OUTPUT SP AN: 4-20 mA DC CURRENT OUTPUT LIMITS: 3 to 28 mA, typical MAXIMUM LOOP RESIST ANCE: (V supply – 11V)/0.020A = ohms LOAD RESIST ANCE EFFECT [...]

Appendix A Intrinsically Safe Interconnection Diagram 29[...]

WARRANTY / DISCLAIMER OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for a period of 13 months from date of purchase. The OMEGA ® W ARRANTY adds an additional one (1) month grace period to the normal one (1) year product warranty to cover handling and shipping time. This ensures that OMEGA ’ s custo[...]

Where Do I Find Everything I Need for Process Measurement and Control? O M EGA…Of Course! Shop online at omega.com TEMPERA TURE 䡺 ⻬ Thermocouple, RTD & Thermistor P r obes, Connectors, Panels & Assemblies 䡺 ⻬ W ire: Thermocouple, RTD & Thermistor 䡺 ⻬ Calibrators & Ice Point References 䡺 ⻬ Recorders, Controllers &am[...]