Watlow Series 942 Controller

Other calibrations (RTD/process input/output)

RTD calibration: Use a 1K Ω precision resistance box to connect terminals 4-6, and input low/high resistance values according to the rLO/rHI parameters (refer to Table 7 in the manual).

4-20mA input calibration: Short circuit terminals 2-3, output 4.00mA (4A parameter) and 20.00mA (20A parameter) from the current source, and calibrate sequentially.

Process output calibration: Connect a multimeter and a matching resistor (such as 4-20mA connected to a 470 Ω resistor), adjust the output to the target value (such as 4.00mA/20.00mA) according to the O1LO/O1HI parameters.

Maintenance and Precautions

routine maintenance

Regular inspection: Check whether the sensor wiring is loose or corroded, whether the panel screws are tightened, and whether the heat dissipation is good.

Battery replacement: Lithium batteries (with backup operating parameters) have a lifespan of about 10 years. In case of abnormal Pout or Run parameters, they need to be returned to the factory for replacement.

Cleaning and maintenance: Wipe the panel with a dry soft cloth to prevent liquid from seeping into the interior of the equipment; Avoid using in damp, dusty, and corrosive environments.

Safety precautions

Disconnect the power supply before wiring, strictly follow NEC and local electrical regulations, and ensure reliable grounding (to avoid electric shock and interference).

The front plate screws should only be rotated 90 °, and excessive force should be avoided to avoid damaging the chassis locking structure.

Mercury relays are only suitable for resistive loads and are prohibited from being used for inductive loads (such as motors without buffering).

Calibration and maintenance must be carried out by professional personnel, and unauthorized disassembly of the equipment casing is prohibited (which may affect warranty).