Endress+Hauser Omnigrad T TR25 Technical Information
Technical Information
omnigrad T TR25
Thermometer without extension neck
Threaded connection under the head
®
PCP (4...20 mA), HART
or PROFIBUS-PA® electronics
Temperature sensors TR 25, series
thermometers suitable for almost all industrial processes and
generic applications thanks
They are made up of a measurement probe without a protection
well, and a housing, which may contain the transmit
version of the variable measured.
Application areas
• Fine chemicals industry
• Light energy industry
• General industrial services
• Environmental engineering
Omnigrad
to their modular structure
T, are resistance
.
ter for con-
Features and benefits
• SS 316L/1.4404 for probe "wetted" parts
• The most common compression junctions are supplied as
standard; others are available upon request
• Insert (not replaceable) in mineral oxide with a diame-
ter of 6 mm
• Customized immersion lenght
• Probe end with reduced diameter for a faster response time
• Surface finishing down to Ra < 0.8 μm
• Stainless steel, aluminium or plastic housing, with protection
grade from IP65 to IP67
• Replaceable mineral insulated insert, with diameter 6 or 3 mm
• PCP (4...20 mA, also with enhanced accuracy), HART® and
PROFIBUS-PA® 2-wire transmitters
• Pt 100 sensing element with class A accuracy (DIN EN 60751)
or 1/3 DIN B
• Pt 100 wire wound (-200...600°C) or thin film (-50...400°C)
• Double Pt 100, for redundancy purposes
• Single Pt 100 with 4 wires connection, double Pt 100 with 3
wires
• EA calibration certificate
TI 269T/02/en
60020989
omnigrad T TR24
Function and system design
Measuring principle In the RTD (Resistance Temperature Detector) thermometers, the sensing element consists of an electrical
resistance with value of 100 Ohm at 0°C (called Pt 100, in compliance with standard DIN EN 60751) which
increases at higher temperatures according to a coefficient characteristic of the resistor material (platinum).
In industrial thermometers that comply with the DIN EN 60751 standard, the value of this coefficient is
α = 3.85*10
Equipment architecture The Omnigrad T TR 25 temperature sensor is made up of a measurement probe and a housing (head), which
may contain a transmitter or the terminals on the ceramic block for electrical connection.
The sensor is manufactured according to standards DIN 43729 (housing) and 43735 (probe) and can therefore
guarantee a good adaptability to the most common industrial processes. The measurement probe consists of a
(replaceable) insert in mineral oxide with a diameter of 3 or 6 mm. The TR 25 can be fitted onto the plant (tube
or vessel) by means of a threaded root fitted below the head, which can be chosen from the most common
models (see section "Structure of the components"). The electrical structure of the thermometer always complies with DIN EN 60751 standard rules. The sensing element is available in two versions with a thin film (TF)
or wire wound (WW), the latter with a large measuring and accuracy range.
The housing can be of different types and materials (plastic, painted aluminium alloy, stainless steel). The way
in which it fits to probe and the cable gland ensure a minimum grade of IP65 (Ingress Protection).
-3
°C-1, calculated between 0 and 100°C.
Fig. 1: TR 25 with the various types of heads, process connections and end parts of the probe
Material • Wetted parts in SS 316L/1.0004
Weight From 0.5 to 2 kg for standard options.
Electronics
The required type of output signal can be obtained by choosing the correct head-mounted transmitter.
Endress+Hauser supplies "state-of-the-art" transmitters (the iTEMP® series) built in 2-wire technology and
with 4…20 mA output signal, HART
using a personal computer through the ReadWin® 2000 and FieldCare public domain softwares (for transmitters 4…20 mA and HART®) or the CommuWin II software (for PROFIBUS-PA® transmitters). The HART®
transmitters can also be programmed with the hand-held operating module DXR 275 (Universal HART
municator). A PCP (4…20 mA, TMT 180) model with enhanced accuracy is available. In the case of PROFIBUS-PA® transmitters, E+H recommends the use of PROFIBUS® dedicated connectors. The Weidmüller type
(Pg 13.5 - M12) is provided as a standard option. For detailed information about transmitters, please refer to
the relevant documentation (refer to the TI codes at the end of the document).
If a head-mounted transmitter is not employed, the sensor probe can be connected through the
terminal block to a remote converter (i.e. DIN rail transmitter).
®
or PROFIBUS-PA®. All of the transmitters can be easily programmed
®
Com-
2 Endress+ Hauser
omnigrad T TR24
Performance
Operating conditions
Accuracy
Operating condition Product type Material Value or data
Ambient temperature housing without head-mounted transmitter metal housing -40÷130°C
plastic housing -40÷85°C
housing with head-mounted transmitter metal or plastic housing -40÷85°C
housing with display metal housing -20÷70°C
Process temperature Same of measurement range (see below)
Maximum Process pressure 4 MPa (40 bar) at 20°C
Maximum flow velocity The highest flow velocity tolerated by the insert diminishes with increasing lengths of the probe
Shock and vibration resistance According to DIN EN 60751 3 g peak / 10÷500 Hz
exposed to the stream of the fluid.
Probe maximum error type WW - Range: -200 to 600°C
Cl.
A
Cl.
1/3 DIN B
3σ = 0.15+0.0020ItI -200…600°C
3σ = 0.10+0.0017It|
3σ = 0.15+0.0020ItI
-50…250°C
-200...-50 /250…600°C
Probe maximum error type TF - Range: -50 to 400°C
Cl.
A
Cl.
1/3 DIN B
3σ = 0.15+0.0020It|
3σ = 0.30+0.0050ItI
3σ = 0.10+0.0017It|
3σ = 0.15+0.0020ItI
3σ = 0.30+0.0050ItI
-50…250°C
+250…400°C
0…100°C
-50...0/100...250°C
250…400°C
(±3s = range including 99.7% of the readings, |t| = absolute value of the temperature in °C)
Transmitter maximum error: See the corresponding documentation (codes at the end of the document).
Display maximum error:
0.1% FSR + 1 digit (FSR = Full Scale Range).
The "4 wires" configuration, provided as a standard connection for the single Pt 100s, excludes additional
errors in every condition (e.g. high immersion depths, long connecting cables without head-mounted transmitters, ...).
Generally speaking, in the "4 wires" configuration there is a higher guarantee of accuracy.
Response time Tests in water at 0.4 m/s (according to DIN EN 60751; 23 to 33°C step changes):
Diameter of stem Pt 100 bulb type Response time
6 mm TF / WW t50 = 3.5 s
90 = 8 s
t
6 mm / 3 mm reduced TF / WW t
50 = 2 s
90 = 5 s
t
Insulation Insulation resistance between terminals and probe sheath > 100 MOhm at 25°C
(according to DIN EN 60751, test voltage 250 V) > 10 MOhm at 300°C
Self heating Negligible when the E+H iTEMP® transmitters are employed.
Endress+ Hauser 3
omnigrad T TR24
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Installation
The Omnigrad T TR 25 thermometers can be mounted on pipes, vessels or other plant parts that may be necessary, by means of compression junctions or thermowells.
The absence of the extension neck (situated between the process connection and the head) may expose the
housing to overheating. To ensure that the head temperature does not exceed the limit values defined in paragraph "Operating conditions", refer to figure 2.
In the case of ATEX-certified components (transmitter, insert), please refer to the relevant documentation (refer
to the code at the end of this document).
Immersion depth may have an effect on the accuracy of the measurement. If the immersion is too low, an error
may be generated in the temperature recorded due to the lower temperature of the process fluid near to the
walls and heat transfer, which takes place through the sensor stem.
The incidence of such an error can be not negligible if there is a big difference between the process temperature
and the ambient temperature. To avoid measurement errors of this kind, it is advisable to set an immersion
length (L) of at least 50÷70 mm (without thermowell).
In pipes of a small section the axis line of the duct must be reached and if possible slightly exceeded by the tip
of the probe (refer to fig. 3A-3B). Insulation of the outer part of the sensor reduces the effect produced by a low
immersion. Another solution may be a tilted installation (see fig.3C-3D). For use in the food industry, it is best
to follow the rule h <= d/2.
h
d
ML
d
h
ML
Fig. 2: Installation examples
In the case of two-phase flows, pay special attention to the choice of measurement point, as there may be fluctuations in the value of the detected temperature.
With regard to corrosion, the base material of the wetted parts in contact with the fluid (SS 316L/1.4404, compression junction in SS 316/1.4401 or SS 316L/1.4404 and several types of sleeves) can tolerate the common
corrosive media up to even the highest temperatures. For further information on specific applications, please
contact the E+H Customer Service Department. In the case that the sensor components are disassembled, in
the following reassembly procedure the definite torques must be employed.
This will assure the housings with the IP grade protection defined.
When the surrounding environment has a high humidity rate and the process is at low temperature, a plastic
housing is recommended (e.g. model TA20B) to avoid problems due to condensation.
In the case of vibrations the thin film sensing element (TF) may offer advantages, but the
behaviour
depends on
the intensity, the direction and the dominating frequency in the vibration mode.
The wire wound Pt 100 (WW), besides having a larger measurement and accuracy range, guarantees greater
long term stability.
4 Endress+ Hauser
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