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Thermocouples:
1.
Avoid locating the thermocouple where it will be in a direct flame.
2.
Never insert a porcelain or refactory tube suddenly in a hot area. Pre-heat gradually while installing.
3.
Locate it where the average temperature will be measured. It should be representative of the mass.
If necessary use several thermocouples to obtain the average temperature.
4.
Immerse the thermocouple far enough so that the measuring junction is entirely in the temperature to be
measured: nine to ten times the diameter of the protection tube is recommended. Heat conducted away from the
junction causes an error in reading.
5.
If the thermocouple is mounted horizontally and the temperature is above the softening point of the tube, a
support should be provided to prevent the tube sagging. Otherwise install the tube vertically.
6.
Keep the junction head and cold junction in the approximation of the ambient temperature. Especially in the Noble
Metal Class.
RTDs:
1.
Avoid locating the RTD where it will be in a direct flame.
2.
Locate it where the average temperature will be measured. It should be representative of the mass.
3.
Immerse the RTD far enough so that the measuring point is entirely in the temperature to be measured, i.e. nine to
ten times the diameter of the protection tube is recommended. Heat that is conducted away from the measuring
point causes an error in reading.
Power Supply Wiring:
1.
Use Only Instrument Quality Power Supplies.
2.
A readily accessible disconnect device and a 1A, 250Vac overcurrent device must be in the power supply wiring.
Z-2400-A2 Commissioning.
1)
WARNING: Ensure that all programming is carried out BEFORE any wiring takes place!
2)
Check that the Z-2400-A2I has been set to the correct input ranges and all functions such as Upscale/Downscale
Drive etc. Observe polarity and the correct terminal connections for wiring correctly. Only use certified calibration
equipment. For Thermocouple calibration place the Z-2400-A2I and calibration equipment directly next to each
other, in still air, with no direct sunshine. Allow the CJC junctions to equalise in temperature before commencing
calibration. Lower temperature ranges are affected more by the CJC Junction (allow more time to equalise).
3)
Once the above conditions have been met, and the wiring checked, apply power to the Z-2400-A2 and the loops
and/or sensors. Allow at least a 5 minute warm-up period.
4)
Thermocouple Inputs only: Due to the limits of error in a standard Thermocouple probe, and standard extension
wire and compensating wire, an error can occur. E.g. In a type K Thermocouple installation an error of 2.2°C or
0.75% FSO can occur (whichever is greater).
The Z-2400-A2I has an integral CJC sensor, the enclosure must be assembled and installed where it avoids drafts
and temperature differences across terminals. Once installation is complete, close the cabinet door and allow the
cabinet to reach equilibrium. This may take several hours. Place all the Thermocouple probes into a calibrated
thermal bath at the temperature of interest or use a calibration standard Thermocouple at the same immersion
depth and temperature of interest and adjust the Zero until the two temperatures agree.
5)
Calibration Check: Take a reading of the value being measured on the Z-2400-A2I input, and ensure that this
agrees with the level being indicated by the Z-2400-A2O output. Adjust for any differences. It is recommended to
measure both a high and low value and compare these readings with your calibration device.
Z-2400-A2 Maintenance.
DC Voltage and Current Inputs:
1)
Check the Sensor or Transducer supplying the signal to the Z-2400-A2I for wear or damage and replace if defective.
2)
Check the cables connected to the Sensor or Transducer.
3)
Repeat (5) of commissioning. Do it regularly - at least once per year.
Thermocouple Inputs:
1)
Replace defective protection tubes - even if they look good they may not be air or gas tight.
2)
Check extension and compensating cable circuits, especially cables entering the Thermocouple sensor head.
3)
Do not use the same Chromel-Alumel (Type K) Thermocouple below 540°C if it was used above 860°C.
4)
Repeat (5) of commissioning. Do it regularly - at least once per year.
RTD Inputs:
1)
Replace defective protection tubes - even if they look good they may not be air or gas tight.
2)
Check cables entering the RTD sensor head.
3)
Repeat (5) of commissioning. Do it regularly - at least once per year.
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