Kentec Electronics K-Detect-iON Flammable Gas Detector

Copyright
Copyright © 2025 Kentec Electronics. All rights reserved. Reproduction without permission is prohibited.

Trademarks:
K-Detect-iON is a licensed trademark by Kentec Electronics. All other trademarks or registered marks in this manual belong to their respective manufacturers.

Disclaimer: Information in this document is subject to change without notice and does not represent a commitment on the part of Kentec Electronics. Kentec Electronics provides this document “as is,” without warranty of any kind, either expressed or implied, including, but not limited to, its particular purpose. Kentec Electronics reserves the right to make improvements and/or changes to this manual, or to the products and/or the programs described in this manual, at any time. Kentec Electronics has made this document to the best of its abilities. However, Kentec Electronics assumes no responsibility for its use, or for any infringements on the rights of third parties that may result from its use. This product might include unintentional technical or typographical errors. Changes are periodically made to the information herein to correct such errors, and these changes are incorporated into new editions of the publication.

Introduction

The K-Detect-iON sensor is an advanced, self-calibrating, standalone device specifically designed to monitor flammable gas types in stationary systems. With a user-settable Slave ID offering 254 combinations and factory calibration, this sensor provides enhanced convenience and reliability. With a recommendation of one sensor per rack for comprehensive monitoring, the K-Detect-Ion sensor is an indispensable tool for critical facilities. The sensor can be configured to detect different gases based on specific customer needs. Listed to UL2075 and calibration-free flammable gas sensor designed to detect the presence and measure the concentration of flammable gases in non-hazardous critical facilities from 0-100% LEL. Patent Pending.

All about K-Detect-iON

Certifications and Calibrations

• ETL listed to UL 2075
• IEC60068-2-30, IEC 60068-2-6, IEC 61000-4-4, IEC 61000-4-5, IEC 61000-4-6
• Compliant with EMC directive (EU) 2014/30 – EN50270:2015, EN55032:2015, EN55035:2017
• Compliant with Low Voltage Directive (EU) 2014/35 – EN61010:2010
• REACH compliant
• RoHS 3 compliant

Sensor Metrics

Technical Specification

Environmental Specification

• Hydrogen (H2)

• Methane (CH4)

Physical Specifications

Parts of the K-Detect-iON Sensor

• RJ45 Port – This port serves as the communication with the Base Unit (Not Used).
• LED – The LED provides signals when the sensor is ready for operation and alerts when the sensor state is missing, offering users a clear and immediate overview of the sensor’s operational condition.

LED Status Light

Warning – Amber

• Down – Red
• Fault – Red
• Normal Condition – Green
• Gas Cap – The gas cap serves as a protective cover for the sensor, ensuring its durability and safeguarding it from external elements.

Configurable output relays 

• A – Relay A – Alarm
• C – Relay C – Fault
• B – Relay B – Alarm
• Mounting hole – This allows users to mount the sensor according to their preferences, providing flexibility in installation. Please see section 6.2 for different types of mounting options.
• Terminal Block – This block comprises terminals for various connections :
• Terminal 1: 12 to 24V DC power input
• Terminal 2: (B-) Connection
• Terminal 3: (A+) Connection
• Terminal 4: Ground (GND)

Rotary Encoder – The rotary encoder is a user interface component that can be rotated to input or adjust settings, facilitating user interactions with the sensor’s configuration. With user settable address out of 254 combinations.

System Architecture

The core of our system architecture lies in the K-Detect-iON sensor, which operates seamlessly on a direct power supply ranging from 12 to 24V DC. This sensor, specifically designed for monitoring gas levels, serves as a critical component in our setup. The sensor is directly interfaced with an INDUSTRIAL CONTROLLER (ICS) or Modbus Controller, forming a robust connection that facilitates the transfer of real-time data and enables efficient control and monitoring within our industrial environment. Furthermore, the K-Detect-iON sensor enhances its versatility with three normally open relays. These relay outputs contribute to the system’s functionality by providing additional control capabilities. This architecture not only ensures reliable power supply and data connectivity but also equips the system with the ability to actuate external devices or processes through the integrated relay outputs, enhancing the overall efficiency and responsiveness of our industrial control setup.

CH4 Gas Detection: Cross-Sensitivity and Precautionary Measures
Cross-sensitivity occurs when a gas sensor responds not only to its target gas but also to other gases in the environment. This characteristic is particularly important to consider when using gas detection systems in environments where multiple gases may be present. This cross-sensitivity requires careful management to ensure accurate gas detection and system reliability.  Additionally, gas contaminants can impact the performance and longevity of sensors. Below is a list of gas contaminants that should be considered during installation and operation:

• H2S (Hydrogen Sulphide)
• SOx (Sulphur Oxides)
• Cl2 (Chlorine)
• HCl (Hydrogen Chloride)

Here are the list of gases that are cross sensitive to methane (CH4)

• Methane (CH4)
• Hydrogen (H2)
• Carbon Monoxide (CO)
• Propane (C3H8)
• Ethylene (C2H4)
• Ethane (C2H6)
• Hexane (C6H14)
• Benzene (C6H6)
• Toluene (C7H8)
• Xylene (C6H4)
• Ammonia (NH3)
• Hydrogen Sulphide (H2S)
• Acetaldehyde (C2H4O)
• Formaldehyde (CH2O)
• R-22
• R-134a
• R-404A
• R-410A

To address this, specific precautions are necessary. By implementing cautions, users can ensure the sensor operates effectively, providing reliable and accurate measurements even in challenging conditions.

1. Exposure to silicone vapours – if silicone vapours absorbs onto the sensor’s surface, the sensing material will be coated, irreversibly inhibiting sensitivity. Avoid exposure where silicone adhesives, hair grooming materials, or silicone rubber/putty may be present.
2. Highly corrosive environment – high density exposure to corrosive materials.
3. Contamination by alkaline metals – sensor drift may occur when the sensor is contaminated by alkaline metals, especially salt water spray.4. Operation in zero/low oxygen environment – sensors require the presence of around 21% (ambient) oxygen in their operating environment in order to function properly. Sensors cannot properly operate in a zero or low oxygen content atmosphere.
4. Excessive exposure to alcohol – if the sensor is exposed to high concentrations of alcohol (such as 10,000 ppm or more) for a long period of time, the filter may become saturated.
5. Lighter gas exposure test – consumers often check if detectors are actually sensing gas by exposing them to lighter gas (main component is iso-butane). Because the filter will block iso-butane from reaching the sensing element, this test cannot be used with the sensor.

H2 and Other Flammable Gas Detection
Hydrogen (H2) and other flammable gases pose significant safety risks in industrial and commercial settings. Reliable detection systems provide early warnings and ensure safety compliance. Below are the list of the flammable gases:

The H2 and other flammable gas detection is inherently immune to siloxanes and poisoning.

Implementation
In this section, you will gain insights into the practical aspects of deploying our sensor technology. We provide detailed information on how the sensors are installed, including their integration, testing, and commissioning processes. Additionally, you’ll find valuable guidance, ensuring that your team is well-prepared to maximize the sensor’s capabilities effectively. This section serves as a hands-on guide to put our technology to work in your environment.

Preparation
Prior to initiating the installation procedure, it is crucial to ensure that you have all the essential materials and devices readily available.

Devices Needed

• K-Detect-iON

Tools Needed

• Modbus cables
• Screw driver
• Screws, bolts and nuts – for mounting purposes

Things to check

• Ensure that there is no visible damage on any of the devices
• Check the functionality of all network cables and ensure that they are free from any defects that could affect the quality of results.
• Prepare the location or area where you intend to place or install the devices. Adhering to these guidelines will contribute to a successful and trouble-free installation process.

Mounting Installation Guidelines
Our sensors offer flexible mounting solutions, providing you with various options for installation:

Important Note:
To ensure proper safety and functionality, the unit must be grounded to an earth ground during installation. Connect the grounding wire to one of the enclosure mounting holes, using a screw and washer to secure it firmly and provide a reliable connection. Proper grounding is essential for Electrostatic Discharge (ESD) protection and optimal device performance. Ensure the connection complies with local electrical and safety codes and test it before powering the  unit.

• DIN Rail: Ideal for secure, space efficient mounting with compatible enclosures or control panels.
• 0U Rack: Allows for efficient and organized rack-based installation, conserving valuable rack space.
• Wall Mount: Perfect for affixing units to walls, optimizing placement within your environment.
• Magnetic: Offers to convenience of magnetic attachment, making it easy to position the components as needed.
• Magnetic: Offers to convenience of magnetic attachment, making it easy to position the components as needed.

Setting Up

1. Push and hold the orange tab.
2. You may use your finger or you may also use a precision flat screwdriver to perform this action (as shown the image below). This action opens the contact, creating space for the wire.
3. While pushing and holding the orange tab, fully insert the stripped end of the wire into the terminal block. Ensure the wire is properly stripped and aligned. You may use a solid wire with a gauge ranging from 16 to 24 AWG for optimal compatibility.
4. Gently tug on the wire to confirm if it is securely held within the terminal block.

Powering up the K-Detect-iON
The K-Detect-iON sensor introduces a versatile power-on mechanism with two distinct options. The primary method involves powering the sensor through a direct current (DC) source, accommodating voltages within the range of 12 to 24 volts. This feature ensures compatibility with a variety of DC power systems commonly employed in industrial settings, providing users with a reliable and standard power option for seamless integration into existing infrastructures.

Important Note:
The device requires a minimum warm-up period of 2 days in a clean environment to ensure accurate readings. It is crucial to allow the sensor to complete this warm-up period before relying on its readings for precise and reliable information. After the warm-up period, perform a power cycle to ensure the device operates optimally and provides accurate data.

Standalone RS485 Connection (Modbus)
Below is the wiring configuration for the terminal block, that connects the sensor to your desired platform via RS485.

Terminal Block – This block comprises terminals for various connections:

• Terminal 1: 12 to 24V DC power input
• Terminal 2: (B-) Connection
• Terminal 3: (A+) Connection
• Terminal 4: Ground (GND)

Note: Please refer to section 7.1 when inserting wires into the terminal block

To set up the Slave ID address please refer to the image below. Please note that there is a pointer that corresponds to the value that it is set to.

Important Note: The combination of 0 and 0 or F and F are not functional. Please ensure these configurations are avoided to maintain proper operations.

Default Modbus Connection Settings
As a standalone device below are the default thresholds and configurations.

Default Relay Threshold
The relay is triggered based on the flammable gas reading, with the threshold determined by the value of the gas sensor expressed in percentage Lower Explosive Limit (%LEL). For newly purchased sensors, the default settings assign Relay A and B threshold values to CH4, and Relay C to the Fault relay. However, you can customize or adjust both the sensor type and the threshold values to trigger each relay, using the Modbus table in Section 7.4 as a reference.

• Relay A 25% LEL
• Relay B 10% LEL
• Relay C Fault Relay

Default Relay State
The default relay state refers to the initial or resting position of a relay when no external power or signal is applied. This state is typically either normally open (NO) or normally closed (NC), indicating whether the relay allows or interrupts the electrical circuit by default. A power cycle is required after applying any changes or updates.

• Normally Open 00
• Normally Closed 01

Relay Delay
Relay delay is the intentional time interval between the activation signal and the actual switching action of the relay.

Relay Minimum Running Time
Relay minimum running time refers to the minimum duration the relay remains active starting from the moment it is triggered.

Modbus Table

NOTE: To apply changes to the Modbus connection settings, please refer to the following. Note that these changes are only applicable to the following Modbus register addresses (40002, 40003, 40004, 4007, 4008 and 40023). If you customize the Parity, Baud Rate, or Stop Bits settings, these will need to be set up again. Additionally, a reboot is required if changes are made to the Parity, Baud Rate, or Relay Default State. The 40041 register represents the relay status using a bitwise value system, where each relay is assigned a specific value equivalent to Relay 1 = 1, Relay 2 = 2, and Relay 3 = 4. When a relay is energized, its corresponding value is added to the total displayed in the Modbus register. For example, a value of 5 (1 + 4) displayed on the register indicates that Relay 1 and Relay 3 are energized, same with the value of 6 (2 + 4) signifies that Relay 2 and Relay 3 are energized.

Connecting K-Detect-iON to Fire Alarm
When connecting the K-Detect-iON sensor to two fire alarm wires in a terminal block for a series connection, follow these crimping steps:

1. Prepare the wires:
   • Strip the insulation from the ends of the two fire alarm wires to expose the copper conductors. Ensure both wires have the same stripped length for a secure connection.
2. Insert into the Ferrule:
   • Take a 16-24 AWG ferrule connector and insert both stripped wire ends into it. Ensure that the wires are fully inserted and aligned properly within the ferrule.
3. Crimp the Ferrule:
   • Place the ferrule into the crimping tool, aligning it within the correct slot. Squeeze the crimping tool firmly to secure the connection. The ferrule should now hold both wires tightly
4. Verify the Crimped Connection:
   • Check the crimped ferrule to ensure a secure and solid connection, The wires should not be loose or able to slip out.
5. Connect to the Terminal Block:
   • Insert the crimped ferrule into the designated terminal block for the K-Detect-iON sensor.
   • For detailed instructions on properly securing the ferrule in the terminal block, please refer to Section 7.1, which provides step-by-step guidance to ensure a secure and reliable connection.

Testing

Periodic Bump Testing of Sensors
To confirm proper operation and ensure full integration with safety and other systems, periodic bump testing of sensors shall be performed. In the absence of specific code requirements specifying the testing interval, it is  recommended to conduct bump testing at least annually out of an abundance of caution. This testing may beconveniently carried out during scheduled fire safety inspections. Additionally, bump testing shall be performed during the initial setup of the system. For gas calibration, we typically source cylinders through Calgas and for the gas regulator, we utilize a 2.5 LPM regulator from Calgas https://www.calgas.co/6c10

Required equipment:

• Gas sensor
• Gas Bump Adapter (AX-GAS-BUMP)
• Gas tubing (from your local gas supplier)
• Gas valve regulator (300ml/min)
• Gas cannister

Procedure

1. Prepare Workspace:
   • Ensure proper ventilation in the testing area.
2. Prepare the sensor:
   • Remove the gas cap from the sensor by rotating it counter clockwise.
   • Replace it with the gas bump adapter, rotating it clockwise until secure.
3. Connect tubing:
   • After securely attaching the gas bump adapter to the gas sensor, connect one end of the gas tubing to the adapter, and the other end to the gas cannister.
   • Finally, connect the gas sensor to the controller and wait until warm up time is finish.
4. Secure Gas Cylinder:
   • Ensure that the gas cylinder is securely mounted and in a stable position.
5. Perform the Bump Test:
   • Gradually open the cylinder valve to ensure a controlled flow of gas to the sensor. Do not fully open the valve; only open it enough to allow the gas to flow.
   • Let the gas flow until the sensor detects it.
   • Monitor the sensor readings on your monitoring device.
6. Stop Gas Flow:
   • Close the cylinder valve to stop the flow of gas.
7. Verify the Sensor Response:
   • Check the sensor readings. The values should respond to the gas exposure.
   • Ensure that the sensor triggers an alert if configured to do so.
   • (Please refer to section 8.4 Testing via Modbus)

Maintenance

• If the sensor passes the bump test, consider it operational.
• If any issues are identified via the status register during the test, make sure to note what error or value is showing before contacting the manufacturer.

Bump & Calibration gases for CH4
It is recommended to use synthetic air containing approximately 20% VOL oxygen, simulating the conditions of a typical natural environment. It is also recommended to preheat for 7 days or at least 2 days prior in doing the bump testing. While there is no specified gas flow rate, it is advised to maintain a low flow rate, gradually open the cylinder valve to ensure a controlled flow of gas to the sensor. Do not fully open the valve; only open it enough to allow the gas to flow to ensure optimal sensor performance. CH4 Gas Cylinder: 50% LEL – 17L steel (Compatible with 6000 Series Multiflow) https://www.calgas.co/biosystems-54-9079-equivalent

Important note: Results might differ when using target gas mixed with other gases.

Bump & Calibration gases for H2 & other flammable gas detection
To ensure accurate testing, the background gas should remain consistent throughout the procedure by using zero air or the recommended gas mixtures outlined in the table below. The suggested flow rate for the gas valve regulator is 300 mL/min. Refer to the table below for the recommended gas cylinder mixtures suitable for bump testing. H2 Gas Cylinder: 50% LEL – 34L steel (Compatible with 6000 Series Multiflow) https://www.calgas.co/50lel-hydrogen-34l

Important note: Results might differ when using target gas mixed with other gases.

Testing via Modbus
It is advisable to conduct regular assessments of the gas sensor’s performance in critical environments. It plays a crucial role in ensuring the dependability, functionality, and security of systems utilizing Modbus communication. Testing a device via Modbus involves using Modbus commands to read or write data from/to device’s registers. Here’s a general guide on how to perform Modbus testing manually:

Requirements

Modbus Master Device or Software Use a Modbus master device or software to send commands and receive responses. Popular Modbus master software includes Modbus Poll, QMod Master, or any other Modbus testing tool.

• K-Detect-iON

Procedure

1. Identify device registers:
   • In order to identify the device registers, check the Modbus Table in section 7.4 to find the specific registers you need to read or write. These registers store important data like sensor reading, device status, or control information.
2. Confirm Modbus device address
   • Every device on a Modbus network has its own unique address. Make sure you know the address of the device you’re working with.
3. Check communication settings:
   • Please refer to section 7.3.1 to 7.4 to find out the communication settings your device uses, like the baud rate, stop bits, and parity.
   • Next step: Set your Modbus master device or software to use the same settings.
4. Connect the Modbus Master:
   • Physically connect your Modbus master (e.g., computer or controller) to the sensor via terminal block. Please refer to the image below for reference:

Terminal Block – This block comprises terminals for various connections:

• Terminal 2: (B-) Connection
• Terminal 3: (A+) Connection

Note: Please refer to section 7.1 when inserting wires into the terminal block

Launch Modbus master software:

• Launch your Modbus master software on your computer and create a new connection to the sensor.

Configure Connection

• Enter the communication parameters (Baud rate, parity, stop bit) in the Modbus master software to establish a connection.
• For establishing communication between the sensor and the Modbus master, set a unique slave ID by adjusting the rotary encoder according to your preference.
• Once the Slave ID is assigned, enter this designated ID into your Modbus Master configuration to establish
  communication between the sensor and the Modbus Master.
• Note: The Slave ID on the rotary as shown on the example on section 7.3 is set to hexadecimal.
• Next, identify the Modbus register address of the sensor you want to check. For example, if you’re checking the VOC sensor, its address is 30002. Once you have the correct address, enter it into your Modbus master software along with the quantity and scan rate. After configuring these settings, confirm or apply them.
• To retrieve the current sensor value, ensure that you also input the correct data type for the sensor. Once all settings are applied, you will be able to view the real-time sensor values in your Modbus master software.

Identify Relay Register:

• Determine the Modbus register address associated with the relay you want to trigger on the Modbus Slave device.
• For example, the Modbus register address will be 40007 if you want to trigger the Relay A. Please see section 7.4 for reference.
• Note: Check if it’s a discrete input, coil, or holding register. (These are just different types of data).

Write the Modbus Command:

• In the Modbus master software – find the function code for writing to a discrete output (this allows you to control device like relays).
• Enter the Modbus Slave ID, register address, and the command value (the value that will trigger the relay).

Send Modbus Command:

• Trigger the relay by sending the configured Modbus command from the Modbus Master to the Modbus Slave device.
• Monitor the response from the Modbus Slave to ensure successful relay triggering.

Verify the Relay State:

• Check the physical state of the relay on the Modbus Slave device to confirm that it has been triggered.

Triggering Relay using gas bump test:

• Identify the sensor value you wish to test during the gas bump procedure. For more details, refer to number 6.
• Once you’ve identified the sensor, assign it to one of the relays. For example, assign H2 to Relay A threshold. In the Relay A threshold setting, enter 0, since H2 = 0. (please see Modbus table in section 7.4 for reference)
• In Modbus address 40005, which corresponds to Relay A’s threshold, enter your desired value. For this example, set the threshold to 10% LEL
• Apply the gas from your cannister to the sensor (refer to Section 8.1 for gas bump testing). Observe if the H2 value increases, indicating a successful bump test. When the value exceeds the set threshold, such as 10% LEL, Relay A will be triggered.

Documents / Resources

Kentec Electronics K-Detect-iON Flammable Gas Detector [pdf] User Manual K-Detect-iON, K-Detect-iON Flammable Gas Detector, Flammable Gas Detector, Gas Detector

References

• User Manual