Technical Data
CompareThermometer
| Measuring Principle | Resistance Temperature Detector |
| Characteristic / Application | High precision average temperature measurement up to 100 m (328 ft), Options: - Display - Sensor probe height adjustment - Heartbeat Verification + Monitoring |
| Max. immersion length on request | up to 100 m (328 ft) |
| Process connection | Flange: DN50...DN80, ASME 2"...4", JIS 10K Threads: 3/4" MNPT2 M20 |
| Operating temperature range | Options: -40 °C...+75 °C (-40 °F...+167 °F) -40 °C...+100 °C (-40 °F...+212 °F) -55 °C...+235 °C (-67 °F...+455 °F) -196 °C...+100 °C (-321 °F...+212 °F) |
| Accuracy | +/- 0.032 °C (+/- 0.058 °F) |
| Ex - approvals | ATEX, IEC Ex, JPN Ex, UK Ex |
| Certification | Metrological approvals and certifications: NMi, PTB Calibration performed on accredited calibration facilities (acc. to ISO/ IEC 17025) |
Average temperature thermometer Prothermo NMT81, high-precision average temperature measurement
Benefits
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Up to 24 resistance thermometers can be installed for precise asset management
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Corrosion-resistant wetted parts
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Installation opening of only 1-1/4”, minimizing tank manufacturing costs
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Simple installation
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Watertight and dustproof housing
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Redundant resistance thermometer measurement via software algorithms, reducing downtime
Applications
The Prothermo NMT81 is used for average temperature measurement of the medium, with an optional level monitoring function. The instrument has a built-in 2-meter capacitive sensor that continuously measures the level and can output the current level information at any time. The NMT81 high-precision average temperature thermometer, used together with tank gauging instruments (e.g., servo level gauges Proservo NMS80, NMS81 and NMS 83; radar level gauges Micropilot NMR81 and NMR84; and tank-side indicator NRF81), is the ideal choice for custody transfer and inventory monitoring applications.
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High-precision average temperature measurement and water bottom level measurement
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Process connection: flange (nominal size not less than 1-1/4“)
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Temperature range: -40...+60°C (-40...+140°F)
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Measuring height: 100 m (328.08 ft)
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Overall accuracy: ±0.032°C (±0.06°F) with 5-point temperature calibration
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Conversion accuracy (temperature): ±0.025°C (0.045°F)
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Sensor measurement accuracy: ±0.02°C (0.036°F)
Spare Parts & Accessories 11
11 spare parts · click to collapse
| Order code | Description | |
|---|---|---|
| 71487199 | Plug: M20, aluminum, EPDM sealing ringConsists of: blind plug, O-ring PTFE coated 17.0x2.0. Usage: FHX50B, FTL51B, FTL62, FTL63, FTL64, FMG50, FMR60B, FMR62B, FMR63B, FMR66B, FMR67B, NMT81, PMC51B, PMC71B, PMD50, PMD55B, PMD75B, PMD78B, PMP50, PMP51B, PMP71B. | Details |
| 71487201 | Blind plug, NPT1/2, aluminumConsists of: blind plug, PTFE coated. Usage: FHX50B, FTL51B, FTL62, FTL63, FTL64, FMG50, FMR60B, FMR62B, FMR63B, FMR66B, FMR67B, NMT81, PMC51B, PMC71B, PMD50, PMD55B, PMD75B, PMD78B, PMP50, PMP51B, PMP71B. | Details |
| 71487203 | Blind plug, NPT1/2, 316LConsists of: blind plug, PTFE coated. Usage: FHX50B, FTL51B, FTL62, FTL63, FTL64, FMG50, FMR60B, FMR62B, FMR63B, FMR66B, FMR67B, NMT81, PMC51B, PMC71B, PMD50, PMD55B, PMD75B, PMD78B, PMP50, PMP51B, PMP71B. | Details |
| 71439089 | Aluminum cover with glass viewing windowSealing ring: HNBR. Sight glass: plastic. Usage: FHX50B, FMG50, FMR60B, FMR62B, FMR63B, FMR66B, FMR67B, FTL41, FTL51B, FTL62, FTL63, FTL64, NMT81, PMC51B, PMC71B, PMD55B, PMD75B, PMD78B, PMP51B, PMP71B, QWX43. | Details |
| 71435134 | Sealing ring FVMQ, -60°C, 5 pcs. Applicable model: FTL51B.Usage: FHX50B, FMR60B, FMR62B, FMR63B, FMR66B, FMR67B, FTL51B, FTL62, FTL63, FTL64, NMT81, PMD75B, PMD78B, PMP71B. | Details |
| 71458633 | Terminal UnitTo connect FHX50B. Usage: FMR60B, FMR62B, FMR63B, FMR66B, FMR67B, FMG50, NMT81. | Details |
| 71496104 | NMT81 mainboard, HART communication, (excluding HistoROM) | Details |
| 71496118 | NMT81 sensor module | Details |
| 71435772 | Display VU100 without buttons. Suitable for: FMG50, PMC51B, PMC71B,W/o buttons. Usage: FHX50B, FMG50, FMR60B, FMR62B, FMR63B, FMR66B, FMR67B, NMT81, PMC51B, PMC71B, PMD55B, PMD75B, PMD78B, PMP51B, PMP71B. | Details |
| 71496120 | C-ring, NMT81 | Details |
| 71438303 | SunshadeFor dual compartment housing. Usage: FMG50, FTL51B, FTL62, FTL63, FTL64, FMR60B, FMR62B, FMR63B, FMR66B, FMR67B, PMC51B, PMP51B, PMD55B, PMC71B, PMD75B, PMD78B, PMD63B, PMP63B, PMP71B, NMT81. | Details |
Configurator / Comparison
Source: Endress+Hauser public information from the website
Manuals & Documents 4
All documents for this modelCase Studies
Municipal Wastewater Treatment · thermistor — Application Case
Project Overview
The site is the inlet, biological and outlet stages of a municipal plant. The customer wanted thermistor properly configured on the existing plant, with the aim of high-accuracy temperature measurement with platinum resistance elements.
Technical Challenges
What actually causes trouble is high solids and corrosive fractions, with large diurnal flow swings, and effluent parameters drift and probes foul with sludge and biofilm. All of this means the thermistor configuration has to involve choosing Pt100 or Pt1000 by accuracy class, wiring system and insertion depth.
Configuration
Supply and installation were organised through the temperature range: temperature solution matched to measuring point and response needs. On site this meant choosing Pt100 or Pt1000 by accuracy class, wiring system and insertion depth, checked line by line against: stable compliance with Grade 1A discharge limits and online data reporting.
Performance
After commissioning the outcome is clear accuracy advantage at low temperatures, giving tighter process windows, and the readings are now used for process tuning.
Food & Beverage · thermistor — Application Case
Site Conditions
This is a Food & Beverage customer whose plant is at dosing, pasteurising, filling and CIP stages. The main task was high-accuracy temperature measurement with platinum resistance elements.
The Problem
The difficulty lies in syrups, dairy and beverages that scale easily, under strict hygienic requirements; at the same time frequent cleaning demands instruments that withstand hot CIP/SIP caustic cycles. Specification therefore means choosing Pt100 or Pt1000 by accuracy class, wiring system and insertion depth.
What We Did
We took a temperature range approach — temperature solution matched to measuring point and response needs. Delivery was built around choosing Pt100 or Pt1000 by accuracy class, wiring system and insertion depth, with point-by-point checks on: food-safety and hygienic design per 3-A / EHEDG.
Operating Outcome
In service the system performs as intended — clear accuracy advantage at low temperatures, giving tighter process windows, with routine maintenance falling noticeably.
Chemical & Pharmaceutical · thermistor — Application Case
Application Context
reactors, metering vessels and finished-product tanks is a typical Chemical & Pharmaceutical duty. The project started from thermistor, focusing on high-accuracy temperature measurement with platinum resistance elements.
Process Constraints
corrosion plus Ex protection shortens instrument life and makes downtime costly, and highly corrosive media with solvents and crystallisation, partly in explosive atmospheres only amplify it. The thermistor specification must therefore cover choosing Pt100 or Pt1000 by accuracy class, wiring system and insertion depth.
Delivery Approach
Delivery was handled as the temperature range — temperature solution matched to measuring point and response needs. Execution centred on choosing Pt100 or Pt1000 by accuracy class, wiring system and insertion depth, together with Ex certification and GMP traceability of records.
Field Results
Operation shows the benefit clearly — clear accuracy advantage at low temperatures, giving tighter process windows, with confidence in this measuring point improving markedly.
Power & Energy · thermistor — Application Case
Customer Profile
The typical setting in Power & Energy is boiler feedwater, turbine condensate and FGD/DeNOx systems. The measuring point is thermistor; the focus is high-accuracy temperature measurement with platinum resistance elements.
Key Difficulties
Conditions are high temperature and pressure with both steam and saline water and, on top of that, drift under high temperature and pressure, with very costly unplanned outages, which a standard configuration cannot handle for long. The design therefore starts with choosing Pt100 or Pt1000 by accuracy class, wiring system and insertion depth.
Implementation
The scope ran through the temperature range: temperature solution matched to measuring point and response needs. Technically it hinges on choosing Pt100 or Pt1000 by accuracy class, wiring system and insertion depth, and on these requirements: compliance with power-industry codes and unit availability targets.
Customer Benefit
In practice this means clear accuracy advantage at low temperatures, giving tighter process windows, which cut the workload on the site maintenance team.
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