- Trusted Seller Stanford Research Systems SIM918- Manufacturer: Stanford Research
- Model: SIM918
 Input offset voltage <10 µV DC bias current <2 pA Current gain of 106 to 108 V/A 15 fA/√ Hz input noise (108 V/A) Autozero feature Bias voltage input Current preamplifier w/ autozero feature New Smyrna Beach, FL
- Trusted Seller Stanford Research Systems SR640- Manufacturer: Stanford Research
- Model: SR640
 Programmable elliptical Filter High end frequency limit: 100.00kHz | Channels: 2 | Operation modes: LP New Smyrna Beach, FL
- Trusted Seller Stanford Research Systems SR830- Manufacturer: Stanford Research
- Model: SR830
 Lock-In Amplifier High end frequency limit: 102.40kHz | Dynamic reserve: 100 | Min. time constant: 10 usec | Max. time constant: 30 ksec New Smyrna Beach, FL

