Maintenance of M&C SP2006-H/DIL Sampling Probe

Reinstall the dilution block to ensure that the O-ring is in the correct position and tightly pressed in place. Attention: The orifice plate has directionality, and the side with a conical surface or mark should face the intake direction.

Reinstall the dilution block, restore heating and gas supply, and test the vacuum degree.

Experience tip: If there may be easily crystallizable substances (such as NH ₄ Cl) in the process, it is recommended to increase the heating temperature of the probe to above 200 ° C, or choose the 280 ° C version, and keep the dilution gas continuously flowing (without interruption during shutdown) to prevent reflux crystallization.

6.3 Frequent triggering of low temperature alarm

Phenomenon: The temperature controller displays large temperature fluctuations or cannot reach the set value, and the low temperature alarm relay acts.

Possible reasons:

The heating element is damaged (open circuit). Measure the resistance of the heating rod with a multimeter. The resistance of the 230V/800W model is about 66 Ω, and the resistance of the 115V/800W model is about 16.5 Ω. If infinite, replace (spare parts 93S0015 or 93S0017).

PT100 or thermocouple malfunction. Measure the resistance or millivolt signal of the sensor and compare it with the standard calibration table.

Poor thermal conductivity: Thermal grease (93S0018) is not applied between the heating rod and the heating block, or the thermal clamp is not tightly pressed.

Excessive wind speed in the environment leads to rapid heat dissipation, and a windproof cover needs to be installed.

6.4 Low readings during calibration of standard gas

Phenomenon: When a known concentration standard gas is introduced, the downstream analyzer displays a value lower than the theoretical calculated value.

Possible reasons:

Insufficient flow rate of standard gas, incomplete replacement of dilution gas. It should be ensured that the standard gas flow rate is ≥ 3 times the gas flow rate of the orifice plate sample.

There is a leak in the calibration gas circuit, which dilutes the standard gas. Check all joints with a leak detector.

Dilution is greater than actual (i.e. excessive dilution). Check if the dilution gas pressure is too high or if the orifice plate is worn.

The linear deviation of the analyzer itself should be calibrated separately with zero gas and range gas first.

6.5 Backblowing function failure (if configured)

Phenomenon: After starting the blowback, there is no instantaneous increase in filter pressure or poor blowing effect.

Reason:

The pressure of the blowback air source is insufficient (at least 6 bar is required).

The blowback valve (pneumatic or electromagnetic) is not activated. Check the control signal and valve body.

The accumulator tank (if optional) is not pressurized or leaking.

The opening pressure of the check valve (/BB) is 0.7 bar. If the blowback pressure is lower than this value, it cannot be opened.

Suggestions for spare parts selection

Based on on-site maintenance experience, it is recommended to keep the following vulnerable parts on hand (refer to Section 18 of the manual):

Spare part number description, replacement cycle suggestion

90S0020 ceramic filter cartridge 2 μ m 150 mm 3-6 months (depending on dust)

93S0020 O-ring (for dilution block, chamber cover) annually or after disassembly and assembly

93S0045 filter gasket (Viton) ®） Every time the filter element is replaced

When the 93S0015/17 heating rod (230V/115V) malfunctions

When the temperature sensor of 93S0059 PT100 malfunctions

When the 93S4406 dilution block (without orifice plate) is severely corroded

93S4420 complete dilution unit (including specified orifice plate), specify dilution ratio when ordering as needed

Precautions for shutdown and storage

When the system needs to be shut down for a long time or the probe needs to be disassembled:

Close the front-end ball valve and cut off the process gas source.

Keep the dilution gas flowing for more than 30 minutes and blow off the residual sample gas inside the probe.

Turn off the heating power and wait for the probe to cool down to ambient temperature.

Cut off all gas sources such as dilution gas, blowback gas, and standard gas.

If the probe is removed from the flange, the inlet and outlet of the sample gas must be sealed with a protective cover to prevent moisture from entering the corroded interior.

The probe should be stored in a dry, frost free, vibration free room, away from direct sunlight.