60 Getting Started GuideXSA InterfaceE6640A Calibration StatusCertificates of CalibrationCustomers receive 2 to 5 Certificates of Calibration (COCs) with the E6640AEXM test set. The EXM is a scalable test set and can be purchased with 1 to 4TRX modules. The TRX modules, along with the Reference module (suppliedwith each E6640A), are the only items that require calibration, and thereforethey are the only items supplied with a CoC and calibration sticker at shipment.Each E6640A test set is shipped with a yellow envelope which contains yourcalibration certificates; this envelope is labeled (lower right corner) with asticker identifying the unit model number (E6640A) and serial number. Insideeach envelope will be from two to five CoCs: one for the reference module,and one for each of the TRX modules installed in the test set. This packageconstitutes your test set’s calibration data.Figure 3-5 Certificates of calibrationYou may choose to physically attach calibration stickers to your E6640A testset (recommended), or, as many customers do, you may choose to use themodules’ electronic calibration information to identify the calibration status ofany module at any time. The use of electronic calibration information is ofbenefit to those customers that may want to move modules from oneinstrument to another: the calibration date always follows the module.To summarize: calibration of the E6640A is not done at the instrument level,but an E6640A is fully calibrated when all of the modules (Reference moduleand TRX modules) are calibrated. At initial shipment, this information isprovided in the yellow envelope supplied with each unit.
