Palmer Wahl TC622A Pocket RTD Calibrator

A pocket RTD calibrator for transmitters and probes

The Palmer Wahl TC622A is a handheld calibrator that measures or generates RTD temperatures for 12 different sensor types, and resistance, at an accuracy the datasheet states as 0.02 percent. The same datasheet covers its thermocouple sibling, the TC621, which handles 16 thermocouple types and voltage. The TC622A is described as a field tool for quick maintenance and commissioning of temperature transmitters and probes, with a large graphical display and a memory of 10,000 values.

The TC622A is delivered with four alkaline AA batteries, and an optional battery charger supports a rechargeable battery. The datasheet says the calibrators are widely used in the energy field, engineering sector, metal industry and automotive field, and are meant to be used with DATACAL calibration software to display and manage data and to issue customized calibration certificates.

Features

• Adjustable resolution down to 1 mohm (TC622) and values displayed in C, F and ohm.
• Very low temperature coefficient: 7 ppm per C in resistance, with IP54 protection and a robust case.
• Automatic detection of 2, 3 or 4 wire connections, shown on screen; connection through banana plugs or a 4-pin round connector.
• Measurement with a hold function, simulation of ramps, pre-programmed steps and synthesizer values.
• Calibrated sensor database so curves can be corrected according to the corrections on a calibration report.
• Data recorded manually on event or automatically at a programmable frequency, stored with date and time and shown as a list or a curve; 10,000 values.
• Scaling with up to 10 segments, minimum, maximum and average display, and a USB port.

TC622A specifications

Resistive probe specifications

At 23 C plus or minus 5 C with 4-wire probes; resolution 0.01 C; accuracy per 1 year as percent of reading plus a fixed value. Take into account the error of the sensor used and the installation conditions, as the datasheet states.

TC622A or TC621: choosing the right model

• Choose the TC622A for RTD transmitters, resistance thermometers and resistance checks; choose the TC621 for thermocouples and millivolt signals.
• The two models share the same housing, display, 10,000 value memory and IP54 rating, according to the shared datasheet.
• For process signals such as 4-20 mA, look at the P32 or C150 from the same maker.
• Use the sensor correction database when you hold a calibration report for the probe you are checking.

Installation and use notes

• Connect the RTD with four wires when you can, because the accuracy table assumes a four-wire connection.
• To simulate an RTD to a transmitter, keep the transmitter excitation within 0.1 to 1 mA as the datasheet specifies.
• Keep the unit within -10 to 50 C for the stated reference performance.
• Upload recorded data to DATACAL to produce your own calibration certificates.

Applications in Oman and the GCC

In power plants, refineries, desalination and metal industries across the Gulf, technicians use pocket RTD calibrators to verify Pt100 transmitters on cooling water, steam and bearing temperature loops. The IP54 body and stored results suit commissioning walkdowns where records matter.

Selection and installation notes

Calibration and test instruments should be set up before they are relied on. Check the ranges and sockets against the devices you will test, use leads and probes in good condition, let the instrument warm up and stabilise, keep the battery charged and enter the sensor type and scaling correctly before recording a result. Keep the calibration certificate on file and plan the re-calibration interval according to your quality system.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Related items and documents

See more portable test and measurement instruments in our range. The datasheet is attached; Seven Star LLC can quote the TC622A, or the TC621 on request.