Brand: KOBOLD

KOBOLD KEC Thermal Mass Flow Meter for Gases, Modbus

Name: KOBOLD KEC Thermal Mass Flow Meter – Datasheet & Quote
Brand: KOBOLD
SKU: KEC

Description

Thermal mass flow metering for compressed air and process gases

The KOBOLD KEC series are thermal mass flow meters for gases that work on the calorimetric principle: a heated PT45 sensor is cooled by the passing gas, and a PT100 measures the gas temperature. Because the measuring effect is mass-based, no extra pressure or temperature compensation is needed. The sensor has no moving parts, a stainless steel 1.4571 probe tip that is easy to clean, and a measuring span of 1:1000 from 0.1 to 224 m/s.

KEC-1 is the immersion version with a ½” connection for existing lines from ¾” to DN 1000; KEC-2 is the in-line version with an integrated measuring section for DN 15 to DN 80. KEC-3 and KEC-4 are the matching ATEX versions. KOBOLD lists compressed air distribution and leak measurement, nitrogen, argon, carbon dioxide and oxygen, vacuum systems, biogas, natural gas at burners and gas mixtures as applications.

Technical specifications

Parameter	Specification
Measuring principle	Thermal mass flow (calorimetric), no additional pressure or temperature compensation
Measuring range	0.1 to 50 m/s (low speed), 92.7 m/s (standard), 185 m/s (max.) or 224 m/s (high speed), referred to DIN 1343 (0 °C, 1013 mbar)
Accuracy / repeatability	±1.5 % of reading ±0.3 % of full scale; on request ±1.0 % of reading ±0.3 % of full scale / 0.25 % of reading with correct mounting
Response time	t90 below 3 s
Operating pressure	KEC-1: 50 bar (100 bar special version); KEC-2: 16 bar (40 bar special version)
Temperature	Probe -40 to +180 °C (standard); -20 to +120 °C for O2, natural gas, propane, methane, biogas, silicone-free option or ATEX; display -40 to +70 °C
Outputs	Modbus RTU; 2 x 4 to 20 mA galvanically isolated (flow and °C), load 500 Ω; pulse; alarm up to 48 VDC, 0.5 A
Display	2″ TFT colour display, rotatable by 180°; flow, total, velocity and temperature
Counters	Total counter plus freely adjustable counter from 1 minute to 1 day
Supply / protection	18 to 36 VDC, 5 W / IP67
Materials	Aluminium die-cast housing; probe tube stainless steel 1.4571
Connection	KEC-1: G ½ ISO 228 or ½” NPT, probe lengths 160 to 600 mm; KEC-2: DN 15 to DN 80 flanged or R / NPT measuring section
ATEX (KEC-3, KEC-4)	II 2G Ex db IIC T4 Gb; II 2D Ex tb IIIC T90 °C Db

KEC-2 in-line ranges

The in-line section has a removable measuring head, so the unit can be taken out for calibration or cleaning without removing the pipe section. The datasheet gives full-scale values in Nm³/h by pipe size and gas; some examples for air (DIN 1945 / ISO 1217: 20 °C, 1000 mbar) are below.

Pipe	Low speed 50 m/s	Standard 92.7 m/s	Max. 185 m/s	High speed 224 m/s
DN 15	20	45	90	110
DN 25	75	145	290	355
DN 50	320	600	1195	1450
DN 80	765	1420	2840	3440

The datasheet also lists argon, carbon dioxide, nitrogen, oxygen, nitrous oxide and natural gas ranges for DN 15 to DN 80 and a longer gas list on later pages.

Installation and ordering

KEC-1 can be mounted and removed under pressure through a ½” ball valve with a safety ring, and the depth scale helps set the probe to the correct insertion depth. Both versions need a straight inlet section for the stated repeatability. Gas type, inner pipe diameter, reference conditions, zero point and leak flow suppression are set via the display or the PC service software; gas type selection and standard temperature and pressure are changed only with the software.

The order example is KEC-1 S 016 1 L S 0 0: model, display, connection and probe length, speed version, gas type, maximum pressure, calibration and options. A three-point calibration certificate is included; real gas calibration is available for other gases. Confirm before ordering: the gas and its composition, pipe inner diameter, operating pressure and temperature, and whether oxygen service needs the cleaned, oil- and grease-free version.

How the KOBOLD KEC works

A heated sensor sits in the gas stream. Moving gas cools the sensor, and a second sensor measures the gas temperature. The power needed to keep the temperature difference constant depends on the mass of gas passing the probe. The electronics turn this into flow, total and velocity values.

Where the KEC is used

Compressed air distribution
Compressed air leak measurement
Nitrogen, argon and carbon dioxide lines
Biogas and natural gas at burners
Vacuum systems and gas mixtures

Selection checklist for the KEC

Gas type
Velocity range
Line size
Immersion or in-line version
Operating pressure
Gas temperature
Output signals
Supply voltage

Installation, commissioning and maintenance notes for the KEC

Mount the probe in a straight run of pipe with enough straight length before and after it. Set the probe depth and the flow direction according to the manual. Connect the supply and the outputs and check the reading against a known flow. Clean the probe tip at regular intervals.

Requesting a quotation for the KOBOLD KEC

Please send the gas, the line size, the pressure, the temperature and the output you need. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

KEC meter type

It is a thermal mass flow meter for gases.

KEC measuring principle

It works on the calorimetric principle.

KEC sensors

A heated PT45 sensor is cooled by the gas and a PT100 measures the gas temperature.

KEC compensation

Because the effect is mass-based, no extra pressure or temperature compensation is needed.

KEC moving parts

The sensor has no moving parts.

KEC probe tip

The stainless steel probe tip is easy to clean.

KEC measuring span

The measuring span is 1:1000 from 0.1 to 224 m/s.

KEC-1 version

The KEC-1 is the immersion version with a 1/2 inch connection.

KEC-1 line sizes

It fits existing lines from 3/4 inch to DN 1000.

KEC-2 version

The KEC-2 is the in-line version with an integrated measuring section for DN 15 to DN 80.

KEC-3 and KEC-4 versions

The KEC-3 and KEC-4 are the matching hazardous area versions.

KEC response time

The response time t90 is below 3 seconds.

KEC operating pressure

The KEC-1 handles 50 bar and the KEC-2 handles 16 bar.

KEC probe temperature

The standard probe temperature range is minus 40 to plus 180 degrees C.

KEC oxygen and gas limits

For oxygen, natural gas, propane, methane and biogas the range is minus 20 to plus 120 degrees C.

KEC outputs

Outputs are Modbus RTU, two 4 to 20 mA signals, a pulse output and an alarm output.

KEC analog signals

The two 4 to 20 mA signals carry flow and temperature and are galvanically isolated.

KEC display

The 2 inch TFT colour display rotates by 180 degrees.

KEC display values

The display shows flow, total, velocity and temperature.

KEC counters

A total counter and a freely adjustable counter from 1 minute to 1 day are included.

KEC supply

The supply is 18 to 36 VDC at 5 W.

KEC housing

The housing is aluminium die-cast.

KEC probe lengths

Probe lengths of the KEC-1 run from 160 to 600 mm.

Gas meter records for the KEC

Record the gas, the probe depth, the line size and the date of each check.

Choosing the right KEC version

Choose the immersion or in-line version from the line size and whether the pipe can be cut.

Documents and quotation

The KOBOLD KEC datasheet (edition 1/05-2025) is attached to this page. Browse our Flowmeters category for related instruments, or compare with the Sierra SteelMass 640S thermal mass flow meter.

For a quotation, send the gas, pipe size and inner diameter, flow range, operating pressure and temperature, KEC-1 or KEC-2, probe length, outputs and any ATEX requirement.

Datasheets & Documents

Datasheet KOBOLD KEC thermal mass flow meter datasheet Download

Reviews (0)

Reviews

There are no reviews yet.

How would you rate this product?

About brand

KOBOLD Messring GmbH is a German instrumentation manufacturer based in Hofheim am Taunus, founded in 1980 by Klaus J. Kobold. It develops and manufactures instruments for monitoring, measuring and controlling flow, pressure, level and temperature, and the international KOBOLD group serves almost all sectors of industry.

Seven Star LLC is an independent supplier in Muscat. We list selected KOBOLD flow and level instruments for oil and gas, water, power and process plants in Oman and the GCC.

KOBOLD product series

Flow instruments include the TMU Coriolis mass flow meter from 60 to 80,000 kg/h, the KEC thermal mass flow meter for gases, the MIM all-metal magnetic inductive meter with IO-Link, the DRB turbine wheel meter, the DON-H high-pressure oval gear meter for 400 bar, the DOG-4 and DOG-6 oscillation meters for gases, the BGN all-metal variable area meter for up to 350 °C and the KAL calorimetric flow monitor for water.

Level instruments include the NGM guided wave radar transmitter, the NRE 80 GHz non-contact radar, the NMB magnetostrictive transmitter, the NWS tuning fork switch and the NBK-03 bypass magnetic level indicator for pressures up to PN 320.

Where KOBOLD instruments are used

Cooling water and lube oil monitoring on machines, chemical dosing and fuel metering, compressed air and gas consumption, tank and vessel level in process plants, and boiler and condensate systems. Many models carry ATEX or IECEx approvals and offer HART, Modbus or IO-Link.

Ordering KOBOLD instruments: what we need

Send the model code, the medium, measuring range, pressure and temperature, process connection and materials, output signal and any hazardous-area approval needed, and we will prepare a quotation from the KOBOLD datasheet.

Browse KOBOLD products by category: Flowmeters, Level Instrumentation.