The Model 530 Loop Calibrator 4-20 mA Loop Calibrator. MSRP: $529.00 Click here for more information on the Model 530. The Model 510 and 511 RTD Simulators RTD Source. Model 510 MSRP: $330.00 Model 511 MSRP: $440.00 Click here for more information on the Model 510. The Model 520 and 521 Thermocouple Simulators Thermocouple source. Model 520 MSRP: $330.00 Model 521 MSRP: $440.00 Click here for more information on the Model 520/521. The Model 532 Loop Calibrator - With Built in Loop Diagnostics Diagnostic 4-20 mA/V calibrator. MSRP: $649.00 Click here for more information on the Model 532. The Model 535 10-50 Milliamp Loop Calibrator 4-20 10-50 mA loop calibrator. MSRP: $1995.00 Click here for more information on the Model 535.