The Fluke 5440A Low Thermal EMF Test Lead Set is engineered for precision measurement applications where thermal electromotive force minimization is critical. This shielded, two-conductor cable assembly delivers sub-microvolt thermal performance and extreme leakage resistance, making it ideal for calibration, metrology, and sensitive electronic testing with Fluke 5440 Series calibrators.
Technical Specifications
Electrical Performance
• Thermal EMF: Less than 1.3 µV per °C (measured at Tellurium Copper Alloy 145 five-way binding post, half hard)
• Leakage Resistance: Greater than 1.0 × 10¹³ Ω per 100 ft at 45 °C and 75% R.H. (between conductors or between conductor and shield)
Cable Assembly
• Configuration: Two 24 inch (61 cm ± 2.5 cm) short leads and one 48 inch (122 cm ± 2.5 cm) long lead
• Cable Type: Two-conductor shielded (Belden 8719 or RG-58/U equivalent)
• Signal Conductors: 16 AWG tinned copper, 19 × 29 stranding (5440A-7003 model) or AWG 20 stranded tinned conductors (5440A-7002 set)
Connector Options
Spade Lug Configuration (5440A-7003):
• Material: Copper spade lug with gold plating over silver, nickel-free
• Terminal Size: 1/4 inch (6.35 mm) diameter
Safety Type Configuration (5440A-7002 set, 5440A-7004/7005 components):
• Connector Diameter: 4 mm
• Center Conductor: Tellurium copper
• Spring Tip: Beryllium copper
• Feature: Retractable spring-loaded hood
– Key Features
• Dedicated shielded construction with separate guard/shield connection per lead
• Thermal EMF specification below 1.3 µV/°C ensures drift-free measurements across temperature ranges
• Ultra-high leakage resistance (>10¹³ Ω/100 ft) eliminates measurement corruption in high-impedance circuits
• Multiple connector styles accommodate varied terminal geometries on precision instruments
• Tinned copper conductors resist oxidation and corrosion
– Typical Applications
• DC precision calibration and verification
• High-impedance metrology measurements
• Thermocouple and low-level voltage testing
• Temperature-sensitive electronic characterization
– Compatibility & Integration
Designed exclusively as an accessory for Fluke 5440 Series calibrators. Lead lengths support both bench proximity and remote test point access.
