Q. What is the thread size of the protective window?

A. M34 x 1.5 (same as the TX).

Q. I have a T4.0 with Profinet but am unable to communicate with the PLC.

A. First check that the model code ends in - 5. You can make quick test by pinging If you receive a response, this indicates that the Profinet firmware was not loaded. You can also check the firmware revision using DTMD. Profinet firmware is 01.02.1008. Please raise a ticket where we will provide the correct firmware for uploading into the sensor.

Q. When did DTMD start supporting T4.0?

A. v6.0

Q. How does "Field Calibration" work with T4.0?

A. The field calibration function in DTMD v6 is a tool built in to the software for calculating and updating the standard offset and gain parameters (DO and DG) in the device (any "supported" device with offset and gain parameters).  1 point (offset) and 2 point (offset and gain) options are available. After running through the steps of the routine, the offset and gain value are uploaded to the device). These parameters can further be adjusted incrementally via the parameter list.

Q. What connections can I use to run Field Calibration?

A. Any standard way that you connect to DTMDv6 (USB, RS485, Ethernet).

Q. Is there any advantage to any particular connection type?

A. Generally no - except that if there is a very long interval between calibration setpoints due to waiting for a reference source to heat and or cool down, then the ethernet connection may time out during the routine. This may be problematic for 4 pin versions. Note that Profinet and EthernetIP versions can connection to DTMD via the ethernet connection.

Q. How does "Field Calibration" work with T4.0 regarding industrial protocols?

A. Offset and gain values can be defined in the initialization parameters in the respective "project". If the sensor has non-default offset and gain values set before installing into an industrial protocol system, care is needed to ensure that these offset and gain parameters are matched in the project, otherwise the standard values will overwrite the set values. As these values are defined only as initialization parameters, it is not possible to adjust these incrementally or "on the fly" like emissivity or transmissivity:

Q. I have a 2-wire version with emissivity encoder switches. When I select a lower emissivity, the temperature does not change.

A.  1st check that the object is not the same temperature as the ambient temperature. When both are equal, lowering the emissivity will not result in a change. Otherwise, using DTDM v6, check the Emissivity Source parameter. With Rotary switch selected you will see (after updating the parameter list) a change in the value Currently calculated emissivity.

Q. If I change the emissivity parameter setting in the software when Emissivity Source is set to Rotary switch, will the parameter change. Yes and no. You will see the value at Emissivity change, but there will be no effect. You will need to change Emissivity Source to Internal Value

Q. Can I use the XR water cooled jacket with T4.0

A.  Yes. The XR and T4.0 both have a 42 diameter housing and the jackets share the same dimension of 63mm diameter and 108mm length.

Q. Can I use DTMD  5.4.1 with Thermalert 4.0

A.  No

Q. Which is the earliest version of DTMD v6  that is compatible

A.  v6.0 (previously Endurance software)

Q. Table 10-21 of the Thermalert 4.0 manual shows two different transmissivity values of 0.62 and 0.71 for ZnS material?  Is this correct?

A.  The difference in the transmissivity values is due to the different optical models behind. SF and CF provide different optical paths.  With an attached protective window these geometries are not optimal any longer because a part of the incoming IR energy is blocked. This results in different effective transmissivity given in the table. So the root cause of the different values is not the material itself but the limited opening for the optical paths.

Additionally, the  LT-15-SF0 model is a bit special compared to the other SF models because it uses a plastic lens which requires a dedicated lens holder. As a result, the optical path for that unit is already restricted and can not be compromised more when using a protective window.

Q. Can a T4.0 fit in an old Thermojacket (TJ) from a Marathon, TX, MM etc

A. Yes, you need to buy the adapter kit A-TJ-T40-CKIT

Q. Can I reuse the TJ adapters from a TX or XR for a T4.0

A. Yes and no. You can use the nose adapter but no the rear adapter - you still need to buy the kit as the rear adapter is not available separately: