What is ΔT in thermography?

ΔT (delta T) is the temperature difference between the measured component and a reference point (typically a similar component under the same load, or ambient temperature). It is the primary severity indicator in thermographic inspections.

What severity levels are used?

Common severity classification uses four levels: Minor (monitor), Intermediate (plan repair), Serious (repair soon), and Critical (immediate action). The ΔT thresholds vary by component type and industry standards.

What ΔT thresholds apply to electrical panels?

For electrical connections: ΔT 1-10°C = Minor, 10-35°C = Intermediate, 35-75°C = Serious, >75°C = Critical. These thresholds are based on NETA MTS standards and are widely used in electrical thermography.

How does load affect thermography readings?

Temperature rise is approximately proportional to the square of the current (I²R heating). When equipment is not at full load, findings may be worse at full load. Always record the load percentage during inspection and extrapolate to full load conditions.

What are the main standards for thermography?

Key standards include ISO 18434 (condition monitoring by thermography), NETA MTS (electrical maintenance testing), ASTM E1934 (IR building surveys), and IEC 62446 (PV systems). ISO 18434 provides the overall framework for machine condition monitoring using IR.

मुक्त अभियांत्रिकी साधन

थर्मोग्राफी तापमान मर्यादा

ISO 18434 नुसार इन्फ्रारेड तपासणी निष्कर्षांचे वर्गीकरण करा. घटकाचा प्रकार आणि संदर्भापेक्षा मोजलेले ΔT प्रविष्ट करून तीव्रता वर्गीकरण आणि शिफारस केलेली कृती मिळवा.

ISO 18434NETA MTSIR तपासणी

घटक प्रकार

संदर्भापेक्षा ΔT (°C)

द्रुत परिस्थिती

वर्गीकरण

तीव्रता

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मोजलेले ΔT

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प्राधान्य

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शिफारस केलेली कारवाई

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या घटकासाठी तापमान उंबरठे

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तापमान गेज

विद्युत घटक (NETA MTS)

ΔT (°C)	तीव्रता	प्राधान्य	क्रिया
1–10	किरकोळ	4	निगराणी ठेवा, सोयीच्या वेळी दुरुस्ती करा
10–35	मध्यम	3	पुढील नियोजित शटडाउनमध्ये दुरुस्तीची योजना करा
35–75	गंभीर	2	शक्य तितक्या लवकर दुरुस्ती करा
>75	गंभीर	1	तत्काळ कारवाई — बिघाड/आगीचा धोका

यांत्रिक घटक

घटक	किरकोळ	मध्यम	गंभीर	गंभीर
मोटर बॉडी	<10°C	10–25°C	25–40°C	>40°C
बेअरिंग हाउसिंग	<10°C	10–20°C	20–35°C	>35°C
कपलिंग	<5°C	5–15°C	15–25°C	>25°C
स्टीम ट्रॅप	<20°C	20–40°C	40–60°C	>60°C
इन्सुलेशन	<5°C	5–15°C	15–30°C	>30°C

Thermography Temperature Limits per ISO 18434 | Vibromera

Published by Nikolai Shelkovenko on फेब्रुवारी 15, 2026 मार्च 5, 2026

वर्गीकरण

विद्युत घटक (NETA MTS)

यांत्रिक घटक

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