In high-precision electronic systems, every nanoamp counts. Low Leakage currents, the small, unintended flow of current between the switch and the coil circuitry, and across the open switch, can cause major headaches in sensitive measurement and test applications. That’s why choosing switching components with minimal leakage is critical. Reed relays, particularly those from Pickering Electronics, offer some of the lowest leakage currents in the industry — often in the picoamp range. In this post, we’ll explore why that matters, which applications benefit most, and how Pickering relays are engineered for ultra-low leakage performance.

Why Low Leakage Current Matters

Leakage current becomes significant when:

• Measuring extremely low signals (e.g. nanoamps or microvolts)
• High density applications where the leakage current across each device can be in parallel with each other resulting in an overall high value.
• Performing high impedance measurements
• Using long hold times in sample-and-hold systems
• Testing insulation resistance or dielectric breakdown
• Working in electrometer-grade instrumentation or ion detection systems
• High Voltage applications – where higher working voltages can result in higher leakage currents. See the table below for more information.

In these contexts, even a few nanoamps of leakage can introduce unacceptable error, reduce measurement accuracy, or mask true signal behaviour.

Applications That Demand Ultra-Low Leakage

Reed relays with minimal leakage current are ideal for:

• Semiconductor parametric testers – Leakage skews voltage/current characteristics at nano/microamp levels.
• Data Acquisition Equipment – Noise can interfere with low-level signals.
• Medical instrumentation – Devices such as EEG or ECG monitors depend on precise low-level signal integrity.
• Electrometer and picoammeter designs – Require high isolation and virtually no leakage for sub-nanoamp accuracy.
• High impedance or floating node measurements – Where any parasitic path can affect results.
• Photodiode and ion chamber measurement systems – Where leakage could falsely increase the detected signal.
• Insulation resistance and breakdown testers – Where low leakage in the test path enables meaningful IR measurements in the teraohm range.

How Pickering Achieves Ultra-Low Leakage Currents

Many relay technologies, including solid-state relays, inherently suffer from higher leakage due to their semiconductor construction. Reed relays, by comparison, offer naturally superior isolation characteristics because their switching element is a physical gap between sealed contacts.

The higher the insulation resistance, the lower the leakage current

Pickering takes this a step further by optimizing every aspect of relay design for ultra-low leakage:

Hermetically Sealed Contacts

Our reed switches are sealed in an inert gas or vacuum environment, preventing oxidation, contamination, or moisture ingress — key causes of leakage.

Superior Insulation Materials

Insulation resistance on Pickering relays is measured in the Teraohm range (>10¹² Ω), drastically reducing leakage even at elevated voltages.

A comparison of leakage current for a device with 10¹² insulation resistance compared to a device with a 10¹³ insulation resistance at increasing switching voltages

Careful Mechanical Design

Minimal creepage and surface paths between contacts and coil terminals reduces risk of leakage through PCB contamination or environmental conditions.

Extensive Testing

Every Pickering relay undergoes 100% testing for insulation resistance and leakage current to ensure consistent, ultra-low leakage performance.

Example Products

Pickering have many popular choices for low leakage applications, offering insulation resistance of >10¹² Ω and open switch capacitance below 1pF. Please explore our range below.