Interlayer Temperature Measurement Using Infrared Thermometers and Thermal Imaging Systems

1. Definition and Fundamental Principles

Interlayer temperature measurement in bimetallic cladding and weld overlay manufacturing refers to the non-contact monitoring and control of substrate and deposited layer temperatures during multi-pass welding, bonding, and post-bonding heat treatment operations. The technology employs infrared thermometers (single-point infrared guns) and thermal imaging cameras (infrared thermal imagers) to capture surface temperature distributions in real time, enabling operators to maintain interlayer temperatures within specified limits defined by welding procedure specifications (WPS) and applicable material standards.

The physical basis of infrared temperature measurement is the Stefan-Boltzmann radiation law, which states that all objects above absolute zero emit electromagnetic radiation whose intensity and spectral distribution are functions of surface temperature. Infrared thermometers measure the radiation energy in a specific wavelength band (typically 2–14 μm) from a single spot and convert it to a temperature reading. Thermal imagers extend this principle across a two-dimensional field of view, producing a spatial temperature map of the workpiece surface at a given instant. The accuracy of both devices depends critically on the emissivity of the target surface, which must be calibrated to match the actual material condition.

In the context of cladding technology, interlayer temperature is the temperature of the previously deposited layer (or base metal) at the time the next welding pass or processing step is applied. Controlling this parameter is essential to prevent excessive grain growth, avoid re-heat cracking, prevent dilution anomalies, and ensure metallurgical compatibility between layers.

2. Category and Business Positioning

This capability falls under the major category of Process Temperature Control and Cooling (过程温控与降温) and is classified under the technical direction of Interlayer Temperature Measurement (层温测量). Within the company's process control architecture, it occupies a critical position at the intersection of real-time monitoring, automated process control, and quality assurance.

The business positioning of this technology is threefold:

Process Integrity Assurance: Ensuring that every weld overlay pass, explosive bonding operation, or post-bonding heat treatment step is performed within the thermally qualified window, thereby protecting the metallurgical integrity of the cladding interface.
Quality System Compliance: Providing traceable, documented temperature records that satisfy NDT and WPS qualification requirements under standards such as ASME Section IX, ASTM A240, and NB/T 47014.
Operational Efficiency Enhancement: Reducing the need for manual thermocouple placement and contact pyrometry, thereby accelerating cycle times while improving data density and spatial coverage.

As noted in the capability entry, this technology is linked to entry number 324 (与324联动), indicating an integrated system architecture where temperature measurement data feeds directly into automated welding control, alarm systems, or process logging platforms.

3. Technical Purpose and Value

3.1 Primary Technical Purpose: Full-Field Non-Contact Monitoring

The stated technical purpose of this capability is full-field non-contact measurement (全场非接触). This distinguishes the approach from conventional point-contact thermocouple methods and provides several decisive advantages:

Complete Spatial Coverage: Thermal imagers capture the entire weld zone and surrounding base metal simultaneously, revealing thermal gradients, hot spots, and cold regions that single-point measurements would miss.
No Physical Contact: Eliminates the risk of thermocouple detachment, oxidation, or contamination of the weld surface, which is particularly critical in high-purity overlay applications.
Real-Time Process Feedback: Enables closed-loop control integration where temperature data triggers automated responses such as welding speed adjustment, cooling water activation, or process halt.
Simultaneous Multi-Parameter Monitoring: A single thermal imager can monitor the interlayer temperature, the weld pool temperature, the base metal preheat level, and the cooling rate in a single acquisition cycle.

3.2 Value Chain Impact

The value delivered by this technology extends across the entire project lifecycle:

Pre-qualification phase: Generates thermal data that supports WPS development and qualification trials by documenting actual interlayer temperature profiles.
Production phase: Reduces rework rates by preventing out-of-specification interlayer temperatures that cause cracking, excessive dilution, or mechanical property degradation.
Inspection and delivery phase: Provides digital temperature records that serve as objective evidence of process conformance for customer audits and regulatory inspections.
Engineering feedback phase: Accumulates process data that feeds into continuous improvement of welding parameters and thermal management strategies.

4. Key Process and Implementation Points

4.1 Single-Point Infrared Thermometer (Infrared Gun) Deployment

The single-point infrared gun is used for rapid spot-checking of interlayer temperatures at specific locations along the weld seam. The operator scans designated measurement points after each pass, recording the temperature before proceeding to the next pass. This method is appropriate for:

Verification of interlayer temperature compliance at discrete points along the weld length.
Quick confirmation that cooling intervals have been sufficient before the next pass.
Complementary monitoring during processes where full-field imaging is impractical due to geometry or shielding constraints.

Key implementation parameters for single-point infrared thermometers include:

Parameter	Typical Specification	Notes
Wavelength Band	8–14 μm (atmospheric window)	Less susceptible to atmospheric absorption; suitable for most metal surfaces
Temperature Range	−20 °C to 1,500 °C (or higher for high-temp models)	Must cover base metal preheat through weld pool temperatures
Accuracy	±1 °C or ±1% of reading	Higher accuracy models preferred for tight interlayer limits
Spot Size / Distance Ratio (D:S)	10:1 to 50:1	Higher ratio enables measurement from greater standoff distance
Emissivity Setting	0.75–0.95 (adjustable)	Critical calibration parameter; see Section 6 for risk discussion
Response Time	<1 second	Ensures captured temperature reflects current surface condition
Data Logging	Internal memory with USB/Bluetooth export	Supports traceability and digital quality records

4.2 Thermal Imager Full-Field Monitoring and Welder Interlock

The thermal imager provides continuous, full-field temperature mapping of the workpiece surface during welding operations. Its integration with the welding power source creates a closed-loop control system where:

The thermal imager continuously captures the temperature distribution across the weld zone and surrounding base metal.
The imaging system processes the thermal data in real time to identify maximum temperatures, average interlayer temperatures, and spatial thermal gradients.
When the measured temperature exceeds the threshold defined in the WPS, the system triggers an automated alarm and may halt the welding process or activate cooling systems.
Temperature data is logged with timestamps and spatial coordinates for post-process analysis and quality documentation.

Key implementation parameters for thermal imaging systems include:

Parameter	Typical Specification	Notes
Detector Type	Microbolometer (uncooled) or InSb/HgCdTe (cooled)	Uncooled for general monitoring; cooled for high-temperature welding
Thermal Resolution	≤25 mK (cooled) / ≤50 mK (uncooled)	Higher resolution detects subtle thermal gradients
Frame Rate	≥9 Hz (typically 30 Hz or higher)	Higher frame rate captures rapid thermal transients
Spatial Resolution	640×480 or higher	Determines minimum detectable hot/cold spot size
Temperature Range	−20 °C to 1,200 °C (multi-range)	Must accommodate preheat through post-weld cooling
Emissivity Calibration	Adjustable 0.10–1.00 with material presets	Must be set for actual surface condition (bare metal, oxide, coating)
Integration Interface	RS-232 / Ethernet / OPC / API	Enables connection to welding controller and data acquisition system
Alarm Threshold	Programmable per WPS	Configurable upper and lower limits with configurable response actions

4.3 Emissivity Calibration — The Critical Accuracy Factor

The capability entry specifically warns about emissivity setting error (注意发射率设定误差). This is the single most common source of measurement inaccuracy in infrared temperature measurement of metal surfaces. The emissivity of a material surface determines the fraction of thermal radiation emitted relative to a perfect blackbody at the same temperature. For metals, emissivity varies significantly with:

Surface finish: Polished steel has emissivity as low as 0.10–0.15, while oxidized or painted steel can reach 0.80–0.95.
Surface contamination: Mill scale, rust, weld spatter, and protective coatings all alter emissivity.
Temperature: Emissivity of bare metals increases with temperature due to oxide formation.
Wavelength: Emissivity is wavelength-dependent; a value calibrated at one wavelength may not apply at another.

Best practices for emissivity management include:

Applying a high-emissivity target (e.g., black paint, kapton tape, or graphite paint) at designated measurement points before welding begins.
Using a calibrated reference target of known temperature (e.g., a heated block with known emissivity) for in-situ verification during the welding process.
Documenting the emissivity setting used for each measurement in the quality record.
Periodically verifying the infrared instrument against a reference thermometer (e.g., a calibrated pyrometer or thermocouple) at known temperatures.

4.4 System Integration with Welding Control (Linkage with Entry 324)

The reference to linkage with entry 324 indicates that the temperature measurement system is not a standalone monitoring tool but is integrated into the broader automated process control architecture. The integration typically involves:

Pre-heat verification: The system confirms that the base metal has reached the specified preheat temperature before welding begins.
Interlayer temperature gating: The welding process is inhibited from proceeding to the next pass until the interlayer temperature has dropped below the maximum allowed limit.
Real-time thermal monitoring: Continuous temperature tracking during welding to detect anomalies such as excessive heat input or inadequate shielding gas cooling.
Post-weld cooling monitoring: Tracking the cooling rate to ensure it remains within the range specified for microstructure control (e.g., to prevent martensite formation in high-carbon steels or to achieve desired grain refinement in overlay alloys).

5. Applicable Standards and Acceptance Criteria

5.1 Welding Procedure Standards

ASME Section IX: Defines requirements for qualification of welding procedures, including interlayer temperature limits for various materials. The qualified interlayer temperature range must be maintained during production welding.
ASTM A397: Specification for welding procedure and performance qualification for carbon, low-alloy, and stainless steel plate. Requires documentation of interlayer temperatures during qualification trials.
NB/T 47014: Chinese national standard for qualification of welding procedures for pressure vessels. Specifies interlayer temperature requirements and documentation expectations.
ASME Section VIII, Div. 1 and Div. 2: For pressure vessel fabrication, interlayer temperature limits are material-specific and must be strictly maintained and documented.

5.2 Material-Specific Temperature Requirements

ASTM A240: For stainless steel clad plates, specifies maximum interlayer temperatures for various grades (e.g., typically ≤250 °C for 304/304L, ≤350 °C for 316/316L, with grade-specific limits for precipitation-hardening grades).
ASME SA-240 / SA-350 / SA-366: Material specifications that define temperature sensitivities for clad and overlay applications.
ASTM A213 / A269: For clad tubing and pipe, interlayer temperature limits are critical to maintaining the integrity of the bond layer.
NACE MR0175 / ISO 15156: For sour service applications, interlayer temperature control is essential to prevent sulfide stress cracking in overlay materials.

5.3 Inspection and Documentation Standards

ASME Section V: Nondestructive examination requirements, including documentation expectations for process parameters that affect NDT acceptance criteria.
API 510 / API 570: For pressure vessel and piping inspection, temperature records support fitness-for-service evaluations.
ISO 17637: For ultrasonic testing of welds, interlayer temperature documentation supports interpretation of UT results.

5.4 Acceptance Criteria for Temperature Monitoring

Acceptance Parameter	Typical Criterion	Verification Method
Interlayer temperature compliance	Within ±10 °C of WPS-specified limit	Infrared measurement at designated points; thermal imager full-field scan
Preheat temperature	Within ±15 °C of specified preheat value	Infrared gun spot check at multiple locations; thermal imager uniformity check
Maximum surface temperature	Not exceeding material-specific maximum (e.g., 250 °C for 304L)	Thermal imager continuous monitoring with automated alarm
Cooling rate	Within specified range (e.g., 10–50 °C/min for certain overlay grades)	Thermal imager time-series analysis
Instrument calibration validity	Calibration certificate current; traceable to national standard	Calibration records; in-situ verification against reference thermometer

6. Common Risks and Controls

6.1 Emissivity Error

Risk: Incorrect emissivity setting leads to systematic temperature measurement error. For example, measuring bare polished stainless steel with an emissivity setting of 0.95 (appropriate for oxidized surfaces) will overestimate the actual temperature by 50–100 °C, potentially leading to unnecessary process delays or, conversely, missed exceedances if the setting is too low.

Controls:

Mandatory application of high-emissivity targets at measurement locations before welding.
Periodic in-situ verification using a calibrated reference thermometer.
Documentation of emissivity settings in the quality record for each production run.
Training of operators on the effects of surface condition on infrared measurement accuracy.

6.2 Atmospheric Interference

Risk: Water vapor, CO₂, and particulate matter in the atmosphere absorb and scatter infrared radiation, attenuating the signal reaching the detector. This is particularly problematic in environments with high humidity, smoke from welding processes, or particulate-laden air.

Controls:

Use of infrared instruments with atmospheric compensation algorithms.
Maintenance of short measurement paths where possible (minimizing the distance between the instrument and the target).
Avoidance of measurement through active welding arcs or shielding gas plumes.
Use of optical filters to reject non-thermal radiation (e.g., arc light, reflected solar radiation).

6.3 Reflected Radiation Interference

Risk: Bright surfaces (especially polished metals) reflect infrared radiation from surrounding heat sources (welding arcs, furnaces, hot surfaces), causing the instrument to read a temperature that is higher than the actual surface temperature. This is a well-known problem when measuring low-emissivity metal surfaces.

Controls:

Use of instruments with reflected temperature compensation (RTC) capability.
Shielding of the measurement path from extraneous heat sources.
Use of high-emissivity targets to minimize reflectance.
Positioning of the thermal imager to minimize the angle of reflection from heat sources into the detector.

6.4 Instrument Drift and Degradation

Risk: Infrared detectors degrade over time due to thermal cycling, exposure to high temperatures, and mechanical shock. This leads to measurement drift that may not be detected without regular calibration.

Controls:

Scheduled calibration at intervals specified by the instrument manufacturer (typically 6–12 months).
Use of certified calibration sources (blackbody furnaces or cryogenic sources) traceable to national standards.
Implementation of a calibration management system with traceable certificates.
Pre-use verification checks using a reference thermometer at known temperatures.

6.5 Data Integrity and Traceability

Risk: Incomplete or unverifiable temperature records may not satisfy customer or regulatory requirements for process documentation.

Controls:

Use of data logging instruments with tamper-evident memory or direct connection to a centralized data acquisition system.
Assignment of unique identifiers to each measurement session (linked to work order, weld map, and operator).
Retention of raw thermal image data alongside numerical temperature records.
Integration with the company's quality management system (QMS) for automated record generation.

7. Application Scenarios Across the Three Technology Routes

7.1 TIG/MIG Weld Overlay Applications

In TIG (Gas Tungsten Arc) and MIG (Gas Metal Arc) weld overlay processes, interlayer temperature control is a critical process parameter that directly affects the metallurgical quality of the overlay.

Typical application scenarios:

Multi-pass overlay welding: Each subsequent pass is applied on top of the previous one. The thermal imager monitors the temperature of the previously deposited layer before the next pass begins, ensuring it has cooled below the maximum interlayer temperature specified in the WPS. For example, in 309L/316L overlay on carbon steel, the interlayer temperature must typically remain below 250 °C to prevent sensitization and intergranular corrosion.
Transition layer welding: When a transition layer (e.g., 309L) is deposited between dissimilar materials (e.g., carbon steel and 316L), the interlayer temperature must be tightly controlled to minimize dilution and ensure a sound metallurgical bond. The thermal imager provides full-field monitoring of the transition zone temperature during each pass.
Post-weld heat treatment (PWHT) monitoring: During PWHT of clad plates or overlay weldments, the thermal imager monitors the uniformity of temperature distribution across the workpiece surface, ensuring that the entire component is within the specified temperature range for the required holding time.
Preheat verification: Before welding begins, the infrared gun verifies that the base metal has been preheated to the specified temperature at multiple locations across the weld zone, ensuring uniform thermal conditions.

Specific benefits in TIG/MIG overlay:

Reduction of rework due to interlayer temperature exceedances, which can cause cracking, excessive grain growth, or loss of corrosion resistance.
Enabling of higher deposition rates by providing confidence that interlayer temperatures are within limits, reducing the need for conservative cooling intervals.
Support for automated welding systems by providing real-time temperature feedback for closed-loop control.
Generation of digital temperature records that satisfy ASME Section IX and NB/T 47014 qualification requirements.

7.2 Hydraulic Explosive Bonding Applications

In hydraulic explosive bonding (also known as hydraulic explosion bonding or hydraulic shock bonding), the interlayer temperature measurement technology is applied primarily during the pre-treatment and post-treatment phases of the bonding process.

Typical application scenarios:

Base metal temperature verification: Before the explosive bonding event, the infrared thermometer verifies that the substrate and cladding layers are at the specified temperature. Some bonding processes require specific temperature ranges to optimize the plastic deformation and bonding quality at the interface.
Post-bonding temperature monitoring: After the explosive bonding event, the thermal imager monitors the temperature distribution across the bonded surface. This is critical for identifying any localized heating that could indicate incomplete bonding, material distortion, or thermal damage to the base metal.
Post-bonding stress relief heat treatment: If a stress relief heat treatment is required after explosive bonding, the thermal imager ensures uniform temperature distribution and monitors the cooling rate to prevent residual stress reintroduction.
Quality verification: The thermal imager can detect bonding defects by identifying regions where the thermal conductivity differs from the expected value. Poorly bonded areas may show different thermal signatures compared to properly bonded regions when subjected to a controlled heat input.

Specific benefits in hydraulic explosive bonding:

Non-destructive verification of bonding quality through thermal signature analysis.
Detection of hidden bonding defects that may not be visible through conventional NDT methods.
Optimization of bonding parameters through correlation of temperature profiles with bonding quality outcomes.
Compliance with API 5L, ASTM A568, and other standards that require documentation of processing temperatures for bonded products.

7.3 Explosion Welding Applications

In explosion welding, the interlayer temperature measurement technology plays a role in both the preparation phase and the post-welding quality assurance phase.

Typical application scenarios:

Explosive charge temperature monitoring: While the explosive event itself is too rapid for real-time infrared monitoring, the thermal imager can be used to verify the temperature of the explosive charge assembly and the surrounding environment before detonation, ensuring that no abnormal heating conditions exist that could affect the detonation characteristics.
Post-explosion surface temperature mapping: Immediately after the explosion welding event, the thermal imager captures the temperature distribution across the bonded surface. This provides critical data on the thermal history of the interface, which directly affects the formation of the characteristic wavy bond pattern and the mechanical properties of the interface.
Post-welding stress relief monitoring: Explosion welding typically requires a stress relief heat treatment to reduce residual stresses. The thermal imager monitors the temperature uniformity and cooling rate during this process, ensuring that the heat treatment is performed within the specified parameters.
Edge trimming and machining temperature monitoring: After explosion welding, the clad plate often requires edge trimming and machining. The infrared thermometer monitors the temperature of the workpiece during these operations to prevent thermal distortion or material property changes at the cladding interface.
Thermal characterization of bonded interfaces: By applying controlled heat to the surface of an explosion-welded clad plate and monitoring the thermal response with the thermal imager, engineers can characterize the thermal conductivity and bond quality of the interface. This technique, known as thermal wave tomography or infrared thermography-based NDT, can detect debonding, voids, and other interface defects.

Specific benefits in explosion welding:

Non-destructive evaluation of bonding quality through thermal wave analysis.
Optimization of stress relief heat treatment parameters through full-field temperature monitoring.
Detection of interface defects that may not be detectable through conventional NDT methods (UT, MT, PT).
Compliance with ASTM A444, ASTM A568, and API 5L requirements for temperature documentation in explosion-welded products.

8. Contribution to Qualification Building, Product Delivery, and Customer Value

8.1 Qualification Building

Interlayer temperature measurement using infrared thermometers and thermal imagers directly supports the qualification of welding procedures and bonding processes under applicable standards:

WPS qualification trials: During WPS qualification trials (per ASME Section IX or NB/T 47014), the thermal imager provides comprehensive temperature data that documents the actual thermal history of the weld. This data supports the determination of qualified interlayer temperature ranges and demonstrates that the procedure can be executed within specified thermal limits.
Procedure performance qualification (PPQ):strong> For PPQ trials, the infrared measurement system provides objective evidence that the procedure can be performed by qualified personnel under production conditions, with interlayer temperatures maintained within limits.

Material qualification: For new material combinations or novel cladding configurations, the thermal imager generates baseline thermal data that supports material qualification and establishes reference temperature profiles for future production.

Regulatory compliance: For products intended for use in regulated industries (nuclear, aerospace, pressure vessels), the temperature measurement system provides the documentation required by regulatory bodies to demonstrate process control and quality assurance.

8.2 Product Delivery

The technology contributes to product delivery in several ways:

Reduced rework and scrap: By preventing interlayer temperature exceedances, the technology reduces the incidence of weld defects that require rework or result in scrap. This directly improves first-pass yield and reduces production cycle times.

Accelerated production: Full-field monitoring eliminates the need for multiple manual thermocouple measurements, reducing the time spent on temperature verification and allowing faster progression through multi-pass welding sequences.

Enhanced process consistency: Automated temperature monitoring and interlock systems ensure that every production run is performed under consistent thermal conditions, reducing variability in product quality.

Improved traceability: Digital temperature records linked to each work order, weld map, and operator provide complete traceability from raw material to finished product, supporting customer audits and regulatory inspections.

8.3 Customer Value

The customer value delivered by this technology is substantial and multifaceted:

Assurance of metallurgical integrity: Customers receive products with verified interlayer temperature control, providing confidence that the cladding interface has been produced under optimal thermal conditions.

Extended service life: Proper interlayer temperature control prevents microstructural degradation, cracking, and corrosion susceptibility, resulting in products with longer service lives and lower lifecycle costs.

Reduced inspection burden: Comprehensive temperature documentation reduces the need for extensive post-weld NDT, as the process control data provides confidence in weld quality. This can translate to reduced inspection costs and faster delivery.

Competitive differentiation: Customers in demanding industries (oil and gas, chemical processing, nuclear power) value suppliers who can demonstrate advanced process control capabilities. The use of infrared temperature monitoring systems positions the company as a technically sophisticated and quality-focused supplier.

Data-driven engineering support: Accumulated temperature data from production runs can be shared with customers to support their own engineering analyses, fitness-for-service evaluations, and process optimization efforts.

9. Implementation Recommendations

9.1 Instrument Selection

Select infrared thermometers with a temperature range that covers the full process window (from ambient to the maximum expected surface temperature, typically up to 800 °C for welding applications).

Choose thermal imagers with sufficient spatial resolution (≥640×480) and thermal sensitivity (≤50 mK) to detect meaningful temperature gradients across the workpiece surface.

Ensure instruments have programmable alarm thresholds and data logging capabilities to support automated process control and quality documentation.

Verify that instruments have appropriate environmental ratings (IP65 or higher) for use in manufacturing environments with dust, moisture, and fumes.

9.2 Calibration and Maintenance

Establish a calibration program with intervals based on instrument usage frequency and criticality of the application (typically 6 months for high-criticality applications, 12 months for general monitoring).

Maintain calibration records traceable to national standards (e.g., NIST-traceable in the United States, or equivalent national metrology institute standards).

Implement a pre-use verification procedure that includes a check against a reference thermometer at a known temperature.

Store instruments in protective cases when not in use and avoid exposure to extreme temperatures or mechanical shock.

9.3 Operator Training

Train operators on the principles of infrared temperature measurement, including the effects of emissivity, atmospheric conditions, and reflected radiation.

Conduct hands-on training on instrument operation, including emissivity setting, measurement technique, and data logging.

Implement a qualification program that certifies operators to perform interlayer temperature measurements independently.

Include infrared temperature measurement in the company's WPS qualification training curriculum.

9.4 System Integration

Integrate the thermal imager with the welding power source controller to enable automated interlayer temperature gating and alarm functions.

Connect the data acquisition system to the company's QMS for automated generation of temperature records and quality documentation.

Implement a data retention policy that ensures temperature records are stored for the required period (typically the life of the product plus a minimum of 5–10 years, depending on industry requirements).

Establish interfaces with the company's NDT systems to correlate temperature data with inspection results for comprehensive quality assurance.

10. Conclusion

Interlayer temperature measurement using infrared thermometers and thermal imaging systems is a foundational capability in modern bimetallic cladding and weld overlay manufacturing. It bridges the gap between process design and process execution, ensuring that the thermal conditions specified in welding procedure specifications are maintained throughout production. The combination of single-point infrared guns for rapid spot-checking and thermal imagers for full-field monitoring provides a comprehensive temperature measurement capability that supports process control, quality assurance, and regulatory compliance across all three of the company's technology routes: TIG/MIG weld overlay, hydraulic explosive bonding, and explosion welding.

The critical importance of emissivity calibration cannot be overstated. Proper management of this parameter is essential to achieving measurement accuracy that supports confident process control decisions. Organizations that invest in rigorous emissivity management, regular calibration, and operator training will realize the full value of infrared temperature measurement technology in their cladding operations.

As the industry moves toward greater automation and digitalization, the integration of infrared temperature measurement systems with welding controllers, data acquisition platforms, and quality management systems will become increasingly important. The company's capability in this area, particularly the linkage with automated welding control systems, positions it to deliver products with superior process control, enhanced traceability, and demonstrable quality assurance that meets the demanding requirements of customers in the oil and gas, chemical processing, nuclear power, and other high-integrity industries.