HLS-442 Model Information

General Description

The HLS-442 is an automotive hydrogen leak sensor designed to monitor hydrogen concentrations ranging from 0% to 4.4% in air. It is developed in accordance with IEC 61508 (SIL2) and is explosion-protected according to ATEX 100a. The sensor transmits the predicted hydrogen concentration to the host via a CAN bus interface. It features self-calibration, which is automatically performed when operated in air with normal hydrogen concentration.

Key Benefits & Features

Sensitivity and Selectivity

• High Sensitivity: Excellent detection of hydrogen gas.
• Concentration Range: 0% to 4.4% H₂ in air.
• Accuracy: ±3000 ppm at normal operation.
• Low Cross Sensitivity: No detection towards HC, H₂S, N₂, CO, CO₂, NOₓ, H₂O.

Performance

• Fast Response Time: Start-up time <5 seconds.
• Speed of Response (t90): <2 seconds.
• Speed of Recovery: <10 seconds.
• CAN Bus Interface: 500 kbit/s (ISO 11898-2).
• PWM Output: Available on request.

Environmental and Safety

• Humidity Influence: Not detectable.
• Operating Temperature Range: -40°C to 85°C.
• Safety Integrity Level: Designed for SIL2 (IEC 61508).
• Explosion Proof: Designed for ATEX zone 2.
• Long-term Stability and Reliability: Expected lifetime of 10 years.
• IP67 Qualified: Dust and water ingress protection.

Applications

The HLS-442 is suitable for detecting hydrogen gas leaks in various applications, including:

• Hydrogen-powered vehicles (cabin ceiling, engine compartment, trunk lid).
• Hydrogen fueling stations.

Block Diagram

The functional blocks of the HLS-442 include:

• Output Switch Connector
• Timer
• Microcontroller
• Watchdog
• Power Supply
• Heater Switch Resistor
• H-Sensor Quantity (TC)
• LDO Voltage Regulation
• Heater Switch Resistor
• H-Sensor Plausibility (FE)
• EMC Filter Protection
• Overvoltage, Reverse Polarity

Installation

The HLS-442 can be installed either sealed against a wall using a gasket (Alt.1) or in an open-air environment (Alt.2). The sensor can be oriented in any direction, but the gas inlet must not be obstructed. Maximum mounting torque is 10 Nm.

Electrical Interface

Electrical Connector

• Connector Type: A2100011199, 6-PIN Code A.
• Matching Receptacle: 6-pin MQS, TE Connectivity AMP p/n 1-967616-1 type.

Pin Assignment

TableCopy

CAN Bus Interface

• Physical Interface: Two-wire balanced, non-terminated.
• Bus Bit Rate: 125, 250, or 500 kBit/s (depending on variant).
• CAN ID Assignment: Determined by the configuration of power supply feeds (UB0, UB1, UB2).

Sensor Status Message (SSM)

• Transmission Interval: 100ms after initial 700ms from power-ON.
• Data Field: 8 bytes.
• H₂ Concentration Encoding: Code = round(H₂/200) + 20.
• Protection Value: 10-bit consistency check.
• CRC16: 16-bit CRC value.

PWM Output (on request)

• Period Time: 255μs.
• Pulse Width Range: 20μs to 240μs (corresponding to 0% to 4.4% H₂).
• Error Indication: 10μs pulse width.

Specifications

Sensor Function

• Target Gas: Hydrogen (H₂).
• Concentration Range: 0% to 4.4% H₂ in air.
• Accuracy: ±3000 ppm.
• Resolution: 200 ppm.
• Speed of Response (t90): <2 seconds.
• Speed of Recovery: <10 seconds.
• Cross-sensitivity: None towards HC, H₂S, N₂, CO, CO₂, NOₓ.
• Start-up Time: <5 seconds (first message after 700ms).
• Expected Lifetime: 10 years.

Electrical

• Supply Voltage: 9V to 16V.
• Supply Current: 75 mA (typical).
• CAN Interface: ISO 11898 Version 2.0 b.
• Programmable CAN ID: On request.
• CAN Bit Rate: 500 kbit/s (125, 250 kbit/s on request).
• PWM Output: On request.
• Connector: A2100011199, 6-PIN Code A.
• Mating Connector: MQS 6-pin, AMP p/n 1-967616-1 type A.
• ESD/Reverse Polarity Protection: Yes.

Environmental

• Operating Temperature Range: -40°C to 85°C.
• Storage Temperature Range: -50°C to 85°C.
• Humidity: 5% to 95% (non-condensing).
• Pressure: 70-130 kPa.
• EMC: Automotive requirements.
• IP Code: IP6K7.

Mechanical

• Dimensions (LxWxH): 82.2x42x17.3 mm.
• Weight: 50g.
• Material: PBT GF30.
• Filter Membrane: Pall SUPOR 450R, 0.45 μm.

Handling Instructions

• Prevent Exposure to: Humidity (condensing conditions), dropping, dust, mechanical impact, electromagnetic radiation (RF fields, high magnetic fields).
• Long-term Storage: In nitrogen-filled ESD bags.

Ordering & Contact Information

• Ordering Code: HLS-442.
• Delivery Form: Individually wrapped.
• Delivery Quantity: Single item.