T797 & T798 |
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| TECHNICAL SPECIFICATION (T797 & T798) |
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| Linearization: | Thermocouple and RTD linearization to ±0.05°C. Custom linearization with 22 pt curve (consult factory). | ||
| Input Impedance: | Greater than 1M Ohm | ||
| Output: | Analog, Two-wire 4 to 20mA | ||
| Transmitter Accuracy: | ±0.05% of the millivolt or ohm equivalent input reading, or the value from the Accuracy Table, whichever is greater; plus ±0.05% of the span. For thermocouples, add ±0.5°C (0.9°F) for cold junction effect. Accuracy includes transmitter repeatability, hysteresis and linearity as well as ambient temperature effect. A/D conversion error, analog output error, line voltage effets, humidity effect under non-condensing conditions and vibration effect to 2g's & 500 Hz. | ||
| Transmitter Repeatability: | One-half the transmitter accuracy | ||
| Cold-Junction Compensation: | Digital self-correcting over the ambient temperature range to within ±0.5°C | ||
| Output Ranging Adjustments: | |||
| Analog Zero: | 100% of Sensor range (Non-interacting) Analog Full-scale: Normal or Reverse Acting | ||
| Ambient Temperature Stability: | Self-correcting over operating temperature range | ||
| Long Term Stability: | Deviation per year is less than: 0.025% of the output span ±0.05% of the reading) | ||
| Damping: | Factory selectable constant (63%) from 0 to 32 sec. | ||
| Failsafe: | User settable to 3.6 or 23mA | ||
| Operating Temperature Range: | |||
| Electronics: | -40°C to +85°C, -40°F to +185°F | ||
| Display (full visibility): | -20°C to +70°C, -4°F to +158°F | ||
| Display (with reduced visibility): | -40°C to +85°C, -40°F to +185°F | ||
| Storage Temperature Range: | -50°C to +85°C, -58°F to +185°F | ||
| Mounting Position: | No effect on measurement value | ||
| Weight: | T787: | 6 oz. | |
| T79E-O/D: | 21/2 lbs. | ||
| T79E-1: | 12 oz. | ||
| Isolation: | 500VAC Input to Output | ||
| Power Supply: | The transmitter operates on 12 to 42VDC (30VDC for I/S installations) with no load. Transmitter is protected against reverse polarity connection. | ||
| Load Limitation: | Loop resistance including optional indicator: R(k Ohms) = (Supply Voltage - 12 VDC)/(23mA) | ||
| Electromagnetic Compatability (CE Compliance): | |||
| Transmitter operates within specification in fields from 20 to 1,000MHz with field strengths to 30V/m. Meets EN 50082-1 Generic Immunity Standard and EN 55011 Compatibility Emissions Standard. | |||
| Dynamic Response: | |||
| Update Rate: | 150 milliseconds (7 times per second), typical | ||
| Response to Step Change: | 250 milliseconds minimum; 1 second, typical | ||
| Start-up Time: | 7 sec. Operation to spec in less than 30 sec. | ||
| Ambient Temperature Change: | Selfcorrecting for ambient temperature changes up to 20°C/hr. | ||
| Interchangeability: | Fully interchangeable without field calibration | ||
| Hazardous Location Certifications: | |||
| Explosion Proof: | Explosion Proof Housings available with and without windows; CSA and FM approved for Class I, Div I & II, Groups B, C & D; Class II, Div I & II, Groups E, F,& G, Class III and are rated for NEMA 4X & NEMA 7 environments. | ||
| Nonincendive: | Transmitter is CSA & FM rated nonincendive in Class I, Div II, Groups A, B, C & D and Class II, Div I, Groups F & G, and Class III, Div II, CENELEC Ex N IIC T4-T6 certification pending. | ||
| Intrinsic Safety: | The Intrinsically Safe Rated Models T797-1 & T798-1 Transmitters are CSA and FM rated Intrinsically Safe for Class I, Div I, Groups A, B, C & D and Class II, Div I, Groups E, F & G, and Class III, Div I, Installed in accordance with Drawing #732-0220-00 for T797 and #732-0221-00 for T798. CENELEC EEx ia IIC T4-T6 Intrinsically Safe certification pending. | ||
| Standard Configuration: | |||
| Sensor Input: | J Type Thermocouple | ||
| LRV (4mA): | 40°F Lower Range Value | ||
| URV (20mA): | 200°F Upper Range Value | ||
| Damping: | 0 seconds | ||
| Output Linear with Temperature | |||
| Failsafe Upscale (23mA) | |||
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Programming via
HART Configuring via
Display The display will also indicate the measured temperature even if the signal is in an out of range condition for the output. For example the factory default setting is a J-type thermocouple 40 to 200°F input to 4-20mA output. If the input measures 300°F, which is out of the configured 40 to 200°F range, then the output will be forced to its maximum level 23mA, however the display will accurately read 300.0°F. The displays can be set for degrees F, C, R and K. The two-line display indicates the units and clearly displays the sensor types during configuration. The one line display does not show the units (i.e. F, C, R or K) unless it is physically labeled and the input types during configuration are coded (see user manual for the 4 digit codes). Safe Installations |
The intrinsically safe versions are designed to meet the Entity Parameters necessary for FM, CSA and CENELEC approval (pending) for Class I Division I, Groups A, B, C and D; and Class II, Division I, Groups E, F, & G and Class III Division I, when installed in accordance with Drawing #732-0220-00 for T797 and #732-0221-00 for T798. See the specifications for Nonincendive approval ratings and for the approval ratings of the EP enclosures. The T79X series of smart programmable transmitters offers the features, functions and options required for easy operation in the most demanding applications. Accuracy, repeatability and long term stability performance are essentially the best that technology has to offer. See the Specification section of this data sheet for more details. Application The T797 with the easy field programming display option provides a flexible ‘off the shelf’ solution to the majority of process temperature measurement applications, minimizing inventory requirements for spares. Either mounted in an explosion proof enclosure or wired through intrinsic safety barriers, the T79X series can meet the stringent safety requirements of most hazardous environments. Calibration |
