Smart Temperature Transmitter

Model 21 / 22

Microprocessor-based smart temperature transmitter (Models 21 and 22) accepting RTD, thermocouple, mV and ohm inputs, with 4–20 mA HART output, ±0.03% of span D/A accuracy, self-diagnostics and optional flameproof or intrinsically safe approvals.

Brand: Bont Technologies
Category: Temperature Instruments

Overview

About the Smart Temperature Transmitter 21 / 22.

The smart temperature transmitter is a microprocessor-based, high-performance transmitter that converts RTD, thermocouple, millivolt or resistance inputs into a 4–20 mA signal with HART digital communication. It compensates automatically for ambient temperature and process parameters, and all sensor data (tag number, type, range and so on) is entered, changed and stored in EEPROM. Zero/span, trim, unit and fail mode can all be configured, and self-diagnostics check the sensor, memory, A/D converter and power. Model 21 is a field-mounted transmitter with an aluminium housing; Model 22 uses a plastic housing.

Features

Flexible sensor input: Pt100 RTD (2-, 3- or 4-wire), thermocouple types B, E, J, K, N, R, S, T, mV and ohm
4–20 mA analogue output with HART digital communication
D/A accuracy ±0.03% of span; Pt100 digital accuracy ±0.17 °C
Stability over 2 years: ±0.1% of reading or 0.1 °C, whichever is greater
Configurable zero/span, trim, unit and fail mode (upscale or downscale)
Self-diagnostics for sensor, memory, A/D converter and power
500 Vrms input/output isolation
Waterproof IP67 housing; optional LCD indicator
Explosion-proof and intrinsic safety approvals available, including KOSHA, KTL, ATEX, FM and GOST

Models

Model 21: epoxy-coated aluminium housing, ½-14 NPT or G½ connections, horizontal or vertical sensor position, single or dual element, optional LCD indicator, stainless steel housing and 2" pipe bracket
Model 22: plastic housing, single or dual element

Options

K1: KOSHA flameproof Ex d IIC T6
K2: KTL intrinsic safety Ex ia IIC T5
E1: ATEX flameproof
F1 / F2: FM and FM Canada explosion proof / intrinsic safety

Applications

Air compressors
Pumps of various types
Hydraulic machines
Water treatment plants and water works
Hazardous areas (with approved versions)

LKS supplies the Bont smart temperature transmitter in Malaysia, with installation, calibration and after-sales support. Contact our engineers for sensor selection and a quotation.

Temperature measurement
HART
Hazardous areas
Water & wastewater

Specifications

Models	21 (aluminium housing), 22 (plastic housing)
Pt100 RTD input	−200 … 650 °C, min. span 15 °C; digital accuracy ±0.17 °C (α=0.00385), ±0.16 °C (α=0.00391)
Thermocouple inputs	B 100 … 1820 °C, E 200 … 1000 °C, J 200 … 1200 °C, K 200 … 1350 °C, N 200 … 1300 °C, R 0 … 1760 °C, S 0 … 1740 °C, T −200 … 400 °C; min. span 25 °C
Thermocouple digital accuracy	B ±0.77 °C, E ±0.20 °C, J ±0.25 °C, K ±0.35 °C, N ±0.40 °C, R ±0.60 °C, S ±0.50 °C, T ±0.25 °C
mV input	−10 … 75 mV, min. span 2 mV, ±0.012 mV
Ohm input	0 … 340 Ω, min. span 20 Ω, ±0.35 Ω
D/A accuracy	±0.03% of span
Output signal	4–20 mA DC / HART
Power supply	12 … 45 V DC (rating 24 V DC ±30%)
HART loop resistance	250 … 550 Ω (24 V DC)
Isolation	500 Vrms (707 V DC)
Stability (2 years)	±0.1% of reading or 0.1 °C, whichever is greater
Repeatability	±0.05% of span
Ambient temperature effect	±0.05% of span / 10 °C
Power supply effect	±0.005% of span / V
Operating temperature	−40 … 85 °C (LCD meter −30 … 80 °C)
Humidity limits	5 … 100% RH
Electrical connection	½-14 NPT (G½ adapter option)
Electronics housing	Aluminium (Model 21), plastic (Model 22); stainless steel housing option
O-ring	Buna-N
Protection class	IP67 waterproof
Explosion protection (options)	KOSHA Ex d IIC T6; KTL Ex ia IIC T5; ATEX flameproof; FM & FM Canada explosion proof or intrinsic safety
Weight	Below 1.2 kg (standard), 2.6 kg (SST housing)
Mounting bracket	2" pipe stanchion, angle or flat type

Lifecycle support

Installed, calibrated and maintained.

With more than two decades in valves and instrumentation across a diverse range of industries, we keep instruments accurate and valves healthy, because valve health management is vital for plant safety.

Installation & commissioning
Calibration & testing
Maintenance & overhaul
Dismantling & replacement

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