The Practical Instrument Electronics (PIE) PIECAL 850 multifunction calibrator is a high performance instrument that does the work of 8 single function calibrators while including 10 to 50 mA capability and advanced troubleshooting tools. The PIE 850 is much more than a multifunction calibrator. It is also a loop detective that is able to diagnose common problems that other test equipment cannot find. Whether you have a flooded junction box or unknown ground faults, the PIE 850 can detect it with it's loop diagnostic technology. It also can use the LoopScope to see all the parameters in the loop at a glance; current, voltage, and resistance. The PIE 850 all in one unit includes a milliamp current calibrator, voltage calibrator, thermocouple calibrator, RTD resistance calibrator, frequency calibrator, pH simulator, continuity checker, and pressure calibrator (with accessory pressure modules). It also includes advanced troubleshooting tools to help you uncover undiagnosed loop problems which can potentially lead to dangerous operating conditions or catastrophic results. When you need to find out why a loop is out of control even when all the wiring seems to be in order, turn on the 850's LoopScope and see all the parameters of the loop simultaneously. The LoopScope displays the current, DC voltage, and total resistance in the loop at the same time. Observing the SUPPLY (DC voltage) and the LOAD (resistance) lets you see if the loop power supply has enough capacity to power all the devices in the loop. By observing all three signals at the same time, you can see how the voltage and resistance respond as the current changes. If the voltage drops too far as the current goes up, you may need a power supply with more capacity or the power supply itself may be failing. If the resistance in the loop is too high, you may have more devices in the loop than the power supply can handle or there may be an instrument in the loop that is drawing too much power and requires replacement.