Model 121 specifications
Output
Type: Bipolar, DC current source
Current ranges: 13 fixed ranges of 100 nA, 300 nA, 1 µA, 3 µA, 10 µA, 30 µA, 100 µA, 300 µA, 1 mA, 3 mA, 10 mA, 30 mA, 100 mA, and a user-programmable
range
Accuracy: 0.05% on 10 µA range, 0.5% on 100 nA and 300 nA ranges, 0.1% on all other ranges
Compliance voltage: ±11 V up to 30 mA, ±10 V up to 100 mA
AC current ripple: <0.1% on 100 nA and 300 nA ranges, <0.01% on all other ranges in properly shielded system
Current ripple frequency: Dominated by line frequency and its harmonics
Temperature coefficient: 0.03% of range/°C for the 100 nA range, 0.01% of range/°C for all other ranges
Line regulation: <0.01% change in output for 5% change in the DC input voltage
Load regulation: <0.01% change in output current over the full-scale range
Stability (24 h): 0.05% on 100 nA range, 0.01% per day on all other fixed ranges
Settling time: <300 ms for full-scale change in current; <100 ms for 10% change in current
Connector: Detachable terminal block
Maximum load: 300 kΩ
User setting
Programming
Operation: Output current settable via computer interface
Resolution: 3 significant digits
Accuracy: 0.5% for currents <300 nA, 0.25% for all other currents
Maximum current: 100 mA
Minimum current: 100 nA
Front panel
Display: 6-digit LED display
Display units: mA, µA, and nA
Display update rate: 2 rdg/s
Display annunciators: mA, µA, nA, and compliance
Keypad: 4 full-travel keys
Keypad functions: Range Up, Range Down, Current Polarity, Enable/Disable
Interface
USB
Function: Emulates an RS-232 serial port
Baud rate: 57,600
Connector: B-type USB connector
Reading rate: Up to 10 rdg/s
Software support: LabVIEW™ driver