The IRISS VPFC Series Infrared Inspection Windows are environmentally sealed crystal inspection windows designed to provide convenient access for infrared inspection of electrical equipment. The series is suitable for a range of thermal inspection applications, including higher-temperature applications, shortwave and midwave thermography, and visual inspection.
The VPFC Series uses calcium fluoride (CaF₂) crystal optics and is available in three models: VPFC-50, VPFC-75 and VPFC-100. Each model provides a different viewing aperture to suit different inspection requirements.
Designed for industrial electrical inspection, the VPFC Series provides an environmentally sealed inspection point that can help maintenance teams carry out thermal inspections without routinely opening electrical equipment enclosures.
✔ Environmentally sealed crystal infrared inspection window
✔ CaF₂ (Calcium Fluoride) crystal optic
✔ Available in VPFC-50, VPFC-75 and VPFC-100 models
✔ Viewing apertures from 2.0 to 4.0 inches
✔ IP67 / NEMA 6 environmental rating
✔ Operating temperature from -40°C to +273°C
✔ 316 stainless steel hardware
✔ Automatically grounded design
✔ Suitable for medium and high voltage applications
✔ Supports midwave IR and longwave IR inspection
✔ Supports ultraviolet (UV) inspection
✔ Supports visual inspection
✔ Supports ultrasound inspection
✔ UL Listed
✔ Limited lifetime warranty
✔ Suitable for higher-temperature thermography applications
| Model | VPFC-50 | VPFC-75 | VPFC-100 |
|---|---|---|---|
| General Specifications | |||
| Overall Dimensions | 9.1 cm (3.6 in) Ø | 12.1 cm (4.8 in) Ø | 15.1 cm (5.95 in) Ø |
| Overall Thickness | 2.6 cm (1.0 in) | ||
| IP / NEMA Rating | IP67 / NEMA 6 | ||
| Operating Temperature | -40°C (-40°F) to 273°C (523°F) | ||
| Body Material | UL 94 5VA Nylon (switchgear-grade plastic); -40°C to 273°C; aluminum cover | ||
| Gasket Material | UL 94 5VA TPE; -40°C to 273°C (523°F) | ||
| Hardware Material | 316 Stainless Steel | ||
| Voltage Range | Any | ||
| Automatically Grounded | Yes | ||
| Optic Specifications | |||
| Viewing Aperture Dimensions | 5.1 cm (2.0 in) Ø | 7.6 cm (3.0 in) Ø | 10.2 cm (4.0 in) Ø |
| Optic Material | Calcium Fluoride Crystal (CaF₂); -100°C (-148°F) to 1400°C (2555°F) | ||
| Inspection Capabilities and Applications | |||
| Midwave IR and Longwave IR; Ultraviolet (UV); Ultrasound; Visual Inspection; Medium/High Voltage Applications | |||
Discover the IRISS VPFC Series Infrared Inspection Windows – Designed for Professional Electrical Inspection
Are you looking for a reliable infrared inspection window for electrical equipment that provides convenient access for thermal inspection without routinely opening an enclosure? The IRISS VPFC Series Infrared Inspection Windows are designed to support professional inspection and condition monitoring applications across electrical and industrial environments.
The VPFC Series uses Calcium Fluoride (CaF₂) crystal optics and an environmentally sealed design. The series is available in three models—VPFC-50, VPFC-75 and VPFC-100—with viewing apertures from 2 inches to 4 inches.
The VPFC Series supports midwave infrared (MWIR), longwave infrared (LWIR), ultraviolet (UV), ultrasound and visual inspection, making it a versatile inspection access solution for electrical equipment.
Key Features of the IRISS VPFC Series Infrared Inspection Windows
The IRISS VPFC Series combines CaF₂ crystal optics, environmental sealing and durable construction to support professional electrical inspection applications.
CaF₂ Crystal Optic
The VPFC Series uses Calcium Fluoride (CaF₂) crystal as its optic material.
The optic is specified for temperatures from -100°C to +1400°C, while the complete VPFC window assembly has an operating temperature range of -40°C to +273°C.
The CaF₂ crystal is designed to support higher-temperature applications, shortwave and midwave thermography, as well as visual inspection.
Multiple VPFC Models and Viewing Apertures
The VPFC Series is available in three models to provide different viewing aperture sizes:
- VPFC-50 – 2.0-inch viewing aperture
- VPFC-75 – 3.0-inch viewing aperture
- VPFC-100 – 4.0-inch viewing aperture
This model selection allows users to choose an inspection window according to their equipment and inspection requirements.
Environmentally Sealed Construction
The VPFC Series features an environmentally sealed design that provides an additional layer of protection for the inspection window and equipment in harsher environments.
The series has an IP67 / NEMA 6 rating, supporting its use in demanding electrical inspection environments.
Multi-Technology Inspection Capability
The VPFC Series is designed to support more than infrared inspection.
According to the supplied product information, the series supports:
- Midwave infrared inspection
- Longwave infrared inspection
- Ultraviolet inspection
- Ultrasound inspection
- Visual inspection
This gives maintenance teams flexibility when using different inspection technologies for equipment condition assessment.
Wide Infrared Transmission Capability
The VPFC CaF₂ optic provides transmission characteristics suitable for several infrared inspection applications.
For the 7–14 micron range, the supplied information specifies typical transmission of approximately 40–50%, depending on the sensitivity of the infrared camera detector at different wavelengths.
Durable Industrial Construction
The VPFC Series is designed with materials intended for industrial electrical applications.
Its construction includes:
- UL 94 5VA nylon switchgear-grade plastic body
- Aluminium cover
- UL 94 5VA TPE gasket
- 316 stainless steel hardware
- Automatically grounded construction
Improve Electrical Inspection Efficiency with the IRISS VPFC Series
The IRISS VPFC Series Infrared Inspection Windows provides a dedicated inspection point for electrical equipment.
Instead of routinely opening an equipment enclosure for thermal inspection, an installed inspection window can provide access for compatible inspection cameras while the equipment remains closed.
The manufacturer describes the VPFC Series as supporting closed and guarded NFPA 70E compliant inspections while helping eliminate exposure to live electrical hazards.
This approach can make routine inspection more convenient and support maintenance teams in carrying out regular equipment condition assessments.
Advanced Infrared Inspection for Electrical Equipment
Thermal inspection can provide useful information about abnormal temperature conditions in electrical equipment.
The VPFC Series provides an inspection access point through its CaF₂ crystal optic, supporting both midwave and longwave infrared inspection.
The crystal optic is also specified for higher-temperature applications and shortwave and midwave thermography.
The result is a dedicated infrared inspection solution that can be integrated into an electrical inspection and condition monitoring program.
Flexible Inspection with IR, UV, Ultrasound and Visual Technologies
One of the important advantages of the VPFC Series is its ability to support multiple inspection technologies.
The supplied information identifies compatibility with:
Infrared Inspection
Supports midwave and longwave infrared inspection.
UV Inspection
Supports ultraviolet inspection applications.
Ultrasound Inspection
Ultrasound is included among the listed inspection capabilities.
Visual Inspection
The crystal optic also supports visual inspection.
This makes the VPFC Series useful when an electrical maintenance program uses more than one inspection technology.
Designed for Medium and High Voltage Applications
The VPFC Series is specified for medium and high voltage applications.
The product information lists the voltage range as Any, together with an automatically grounded design.
The manufacturer also identifies the VPFC Series for electrical equipment inspection applications where closed and guarded inspection access is required.
Environmentally Sealed Infrared Inspection Window
The VPFC Series is designed to provide environmental protection around the inspection point.
Its IP67 / NEMA 6 rating is specified for the series, while the environmentally sealed construction provides an additional layer of protection for the window and equipment in harsher environments.
This makes environmental protection an important part of the VPFC Series design.
VPFC Series Models for Different Inspection Requirements
The VPFC Series provides three viewing aperture options.
IRISS VPFC-50
The VPFC-50 features a 2.0-inch diameter viewing aperture and an overall diameter of 3.6 inches.
It is the smallest viewing-aperture option in the VPFC Series.
IRISS VPFC-75
The VPFC-75 features a 3.0-inch diameter viewing aperture and an overall diameter of 4.8 inches.
IRISS VPFC-100
The VPFC-100 features a 4.0-inch diameter viewing aperture and an overall diameter of 5.95 inches.
It provides the largest viewing aperture within the VPFC Series.
VPFC Series Technical Specifications
General Specifications
| Specification | VPFC-50 | VPFC-75 | VPFC-100 |
|---|---|---|---|
| Overall Diameter | 3.6 in (9.1 cm) | 4.8 in (12.1 cm) | 5.95 in (15.1 cm) |
| Overall Thickness | 1.0 in (2.6 cm) | 1.0 in (2.6 cm) | 1.0 in (2.6 cm) |
| IP / NEMA Rating | IP67 / NEMA 6 | IP67 / NEMA 6 | IP67 / NEMA 6 |
| Operating Temperature | -40°C to +273°C | -40°C to +273°C | -40°C to +273°C |
| Body Material | UL 94 5VA Nylon + Aluminium Cover | UL 94 5VA Nylon + Aluminium Cover | UL 94 5VA Nylon + Aluminium Cover |
| Gasket Material | UL 94 5VA TPE | UL 94 5VA TPE | UL 94 5VA TPE |
| Hardware | 316 Stainless Steel | 316 Stainless Steel | 316 Stainless Steel |
| Voltage Range | Any | Any | Any |
| Automatically Grounded | Yes | Yes | Yes |
Optic Specifications
| Specification | VPFC-50 | VPFC-75 | VPFC-100 |
|---|---|---|---|
| Viewing Aperture | 2.0 in (5.1 cm) Ø | 3.0 in (7.6 cm) Ø | 4.0 in (10.2 cm) Ø |
| Optic Material | Calcium Fluoride (CaF₂) Crystal | Calcium Fluoride (CaF₂) Crystal | Calcium Fluoride (CaF₂) Crystal |
| Optic Temperature Range | -100°C to +1400°C | -100°C to +1400°C | -100°C to +1400°C |
Inspection Capabilities of VPFC Series
The VPFC Series supports several inspection methods.
Infrared Thermography
Use the inspection window with compatible infrared cameras for thermal inspection of electrical equipment.
Ultraviolet Inspection
The VPFC Series supports UV inspection as specified by the manufacturer.
Ultrasound Inspection
Ultrasound inspection is also included in the listed inspection capabilities.
Visual Inspection
The CaF₂ crystal optic supports visual inspection as well.

