The Heat Pipe Temperature Test Machine -- also called the temperature difference testing machine, delta-T testing machine, or heat pipe ΔT measurement equipment -- measures the heat transfer rate of finished heat pipes through temperature difference (ΔT) measurement under controlled thermal load conditions. It is the production test station that confirms whether each heat pipe achieves the minimum heat transfer performance required by the thermal solution assembly specification, before the heat pipe is integrated into a CPU cooler, laptop thermal module, or server cooling assembly.
Equipment Specifications -- Two Models
| Specification | Model A: Water Bath (Immersion) Type | Model B: Copper Block Heating Type |
|---|---|---|
| Test Method | Immerse heat pipe in temperature-controlled water bath | Place heat pipe on copper heating block |
| ΔT Formula | ΔT = Water temperature - upper clamping temperature ≤ set value | ΔT measured across heating and ambient points |
| Temperature Range | Room temp to 90°C water | Copper block ≤ 80°C |
| Temperature Tolerance | ±1°C water temperature | Temperature set by copper block control |
| Pipe OD | -- | Ø5 to Ø10 mm |
| Pipe Length | -- | ≤ 500 mm |
| Workstations | 6 stations | 4 to 6 stations |
| Measurement Time | 6 to 7 seconds (adjustable) | Set per test protocol |
| Test Shapes | -- | 2D, 3D |
| Test Angles | -- | Horizontal, vertical (inclinable) |
| Heating Area | -- | 15×30mm horizontal / 15×30mm vertical |
| Software | LabView | LabView |
| Fixture | -- | Magnet-held fixture -- movable to any position |
| Data Storage | Computer storage or printout | Computer storage |
| Batch traceability | Heat pipe batch number + tester ID input | Heat pipe batch number + tester ID input |
| Capacity | 500 pcs/hr | 500 pcs/hr |
| Power | 220V × 1φ × 8 kW | 220V × 1φ × 8 kW |
| Dimensions | 1,600 × 1,200 × 1,500 mm | 1,600 × 1,200 × 1,500 mm |
| Weight | 650 kg | 650 kg |
Two Models Explained -- Water Bath Immersion vs Copper Block Heating: Which Is Right for Your Production?
Model A: Water Bath (Immersion) Type -- Fast Batch Screening at 500 pcs/hr
The water bath model immerses the heat pipe in a temperature-controlled water bath (room temperature to 90 degrees C, tolerance ±1 degree C). The temperature-sensing wire is embedded in the support end with bakelite to measure the upper clamping temperature. ΔT = water temperature minus upper clamping temperature. The ΔT value threshold is set on the computer; heat pipes exceeding the set ΔT threshold are sorted as NG. Measurement time: 6 to 7 seconds per pipe (adjustable). Test data can be stored in the computer or printed out. With 6 workstations operating in parallel, the water bath model achieves 500 pieces per hour -- the fastest temperature test configuration Cooling-Thermal offers, and the correct choice for high-volume production lines running uniform heat pipe product batches where rapid ΔT screening is the primary test objective.
Model B: Copper Block Heating Type -- 2D/3D Geometry, LabView, Inclinable Test Angles
The copper block heating model places the heat pipe on a copper heating block with set temperature (up to 80 degrees C) and time. The machine measures the copper tube temperature and the heat transfer rate within the set period. The magnet-held test fixture can be moved to any position, enabling both horizontal and vertical (inclinable) test orientations for 2D and 3D heat pipes. 4 to 6 workstations. LabView software control. Batch number and tester ID can be input for full traceability. The copper block model is the correct choice for production lines testing multiple heat pipe formats (different ODs, 2D and 3D geometries) where flexible fixture positioning is required, or for applications where test temperature and duration need to be precisely controlled for different product specifications on the same machine.
What ΔT Measurement Tells You -- Heat Transfer Rate, Thermal Conductivity, and Production Pass/Fail
Temperature difference (ΔT) between the heat source end (evaporator) and the cool end (condenser) of a heat pipe is the most direct indicator of heat transfer performance at a given power input. A lower ΔT means better heat transfer -- the heat pipe is moving heat efficiently from evaporator to condenser. A higher ΔT at the same power input means the heat pipe is underperforming -- the evaporator is getting hotter than expected for the given cooling load.
| ΔT Test Result | What It Indicates | Root Cause in Production |
|---|---|---|
| ΔT below threshold (PASS) | Heat pipe transfers heat efficiently; thermal resistance within spec | Correct working fluid fill, intact wick, NCG-free -- all production steps successful |
| ΔT above threshold (FAIL) | Heat pipe thermal resistance exceeds specification | Possible causes: residual NCG / insufficient working fluid / wick damage / contact surface gap |
| ΔT diverges at low power (FAIL) | Evaporator dry-out at below-spec power -- Qmax below specification | Insufficient working fluid fill volume (Step 5) or wick damage (Step 3/4) |
| ΔT inconsistent batch-to-batch | Fill volume or NCG removal process is not under control | Fill machine accuracy (Step 5) or degassing completeness (Step 4/5) needs investigation |
The temperature difference test is the production screening test -- fast (6-7 seconds per pipe), high throughput (500 pcs/hr), confirming every heat pipe meets the minimum ΔT threshold before shipment. It is complementary to, not a substitute for, the full performance test (Qmax and thermal resistance measurement) which is used for qualification, sampling, and R&D applications.
Batch Traceability and Data Management -- Meeting OEM Customer Data Requirements
Both models of Cooling-Thermal's temperature test machine support the batch traceability and data recording requirements that OEM thermal solution customers require from their heat pipe suppliers: batch number input for each production run, tester ID logging for operator accountability, ΔT measurement value recording per heat pipe, and OK/NG judgment stored against each serial or batch record. Test data can be stored to computer or printed directly. For customers requiring integration with factory MES or ERP systems, Cooling-Thermal provides data export in standard formats compatible with downstream quality management systems.
