The Klein Tools NCVT-4IR is a non-contact voltage tester pen with integrated infrared thermometer, designed for electricians and HVAC technicians. It detects AC voltage from 12 to 1000V without direct contact and simultaneously measures surface temperatures from -22 to 482°F using a 4:1 distance-to-spot IR sensor. Rated CAT IV 1000V with IP54 environmental protection and 6.6-foot drop resistance, it delivers LED and audible alerts for voltage detection. The dual-function design eliminates the need for a separate IR thermometer on HVAC service calls. Backed by Klein Tools' 1-year limited warranty.
What does the infrared thermometer add over a standard NCV tester?
The NCVT-4IR detects surface temperature via IR sensor in addition to non-contact AC voltage detection — eliminating the need to carry a separate IR thermometer on HVAC and electrical service calls. The temperature reading requires no physical contact with the surface under test.
What does the 4:1 distance-to-spot ratio mean?
At 4 inches from a surface, the IR sensor reads a 1-inch diameter spot. At 8 inches, it reads a 2-inch spot. Closer measurement gives a more precise, smaller target area — relevant when distinguishing temperature between adjacent components in a panel or HVAC system.
What temperature range does the IR sensor cover?
-22 to 482°F (-30 to 250°C) — sufficient for HVAC applications including refrigerant line surface temperatures, motor housings, breaker hot spots, and heat-generating electrical components. For high-temperature industrial applications, a dedicated IR thermometer with wider range is more appropriate.
How does the NCVT-4IR compare to the NCVT3P?
The NCVT3P adds IP67 waterproofing (vs. IP54 on the NCVT-4IR) and an independently usable flashlight. The NCVT-4IR adds infrared temperature sensing. Choose NCVT-4IR for HVAC or electrical work where thermal scanning is useful; choose NCVT3P for wet environments and situations where flashlight illumination is the priority.
Can it detect low-voltage AC circuits like doorbells or thermostats?
Yes — the 12V AC minimum covers doorbell transformers (16–24V AC) and thermostat wiring (24V AC), the same low-voltage detection range as the NCVT2P and NCVT3P.
What is the rated battery life?
134 hours on 2 AAA batteries — comparable to the NCVT2P (142 hours) and slightly better than the NCVT3P (125 hours with flashlight). The auto-power-off feature extends battery life during idle periods.
# Klein Tools® NCVT-4IR Non-Contact Voltage Tester Pen with Infrared Thermometer, 12 to 1000V AC **Model:** `NCVT-4IR` **Brand:** Klein Tools **Category:** Voltage Tester > The Klein Tools NCVT-4IR is a non-contact voltage tester pen with integrated infrared thermometer, designed for electricians and HVAC technicians. It detects AC voltage from 12 to 1000V without direct contact and simultaneously measures surface temperatures from -22 to 482°F using a 4:1 distance-to-spot IR sensor. Rated CAT IV 1000V with IP54 environmental protection and 6.6-foot drop resistance, it delivers LED and audible alerts for voltage detection. The dual-function design eliminates the need for a separate IR thermometer on HVAC service calls. Backed by Klein Tools' 1-year limited warranty. ## Specifications | Attribute | Value | |---|---| | Product Type | Non-Contact Voltage Tester with IR Thermometer | | Voltage Range Ac | 12–1000V AC | | Ir Temp Range | -22 to 482°F (-30 to 250°C) | | Ir Distance To Spot Ratio | 4:1 | | Frequency | 50–500 Hz | | Safety Rating | CAT IV 1000V | | Ip Rating | IP54 | | Drop Protection Ft | 6.6 | | Dual Range | No | | Display Type | LED | | Battery Type | 2 × AAA | | Battery Life Avg Hours | 134 | | Overall Length In | 6.25 | | Assembled Weight Oz | 2 | | Barcode (UPC) | 092644690617 | | Warranty | 1-year limited | ## What's Included - NCVT tester - 2 × AAA batteries Source: https://www.jaspecs.com/klein-tools/voltage-tester/ncvt-4ir-klein-tools-non-contact-voltage-tester-pen-infrared-thermometer-12-1000v-ac/