HIKVISION DS-2TE127-G4A Reference Blackbody - a look inside .... by Fraser - Page 1
Forum section: electronics / general

author: Fraser
author_rank: Super Contributor
timestamp: December 07, 2022, 06:31:56 pm
content: This is a very quick post to show those who may be interested in what is inside the casing of a HIKVISION DS-2TE127-G4A Reference Blackbody.The DS-2TE127-G4A was created to assist with Fever Screening that used thermal imaging cameras. The Reference Blackbody produces an accurate thermal signature in the cameras field of view that is used by analysis software to improve the cameras thermal measurement accuracy.The Reference Blackbody must be accurate and stable in order to meet the specified medical role. As such these units can be very well made using known quality components and were very expensive. The HIKVISION unit is such a design and is well designed using quality parts.The specification for the HIKVISION Reference Blackbody is as follows:Temperature range: Ambient +5 Celsius to +50 CelsiusTemperature Resolution: 0.1 CelsiusTemperature Accuracy: +/- 0.1 CelsiusTemperature Stability: +/- 0.1 CelsiusEffective Emissivity: 0.97 +/- 0.02Aperture diameter: 70mmPower Supply: 100Vac to 240VacPower Consumption : 20WAs can be seen, the specification is more than adequate to test the measurement accuracy of a thermal imaging camera or IR thermometerInside the units casing there is a well designed layout of components comprising the following main elements:1. MeanWell LRS-50-24 24V 2.2A Switch mode Power Supply2. OMRON E5CC high quality PID temperature controller3. OMRON G3NA-D210B Solid State Relay4. Custom heater assembly incorporating a coated Aluminium emission plate and KAPTON insulated foil element heater.The unit is cooled with a small fan.The temperature to which the PID temperature controller may be set is limited in its settings. These limits may be changed if desired and the design of the heater assembly appears good for at least 100 Celsius if required. I recommend a maximum temperature of 80 Celsius however. The temperature range "as supplied" of Ambient +5C to +50C is still enough for a normal "2-Point" calibrationTo the pictures:

author: Fraser
author_rank: Super Contributor
timestamp: December 07, 2022, 06:33:35 pm
content: Disassembly begins......

author: Fraser
author_rank: Super Contributor
timestamp: December 07, 2022, 06:35:23 pm
content: Continued....

author: Fraser
author_rank: Super Contributor
timestamp: December 07, 2022, 06:38:08 pm
content: Heater and Emission plate Module.Note:a) The PT100 RTD temperature sensor conductors are inside the white PTFE insulated cableb) The black wires connect to the 24V foil heaterc) The hole in the top of the module is for the use of a PT100 calibration thermometer to calibrate and check the accuracy of the BlackBody.d) The heater is a Kapton film coated foil type sandwiched between the back-plate and emission platee) The thermal insulator between the emission plate and the BlackBody front panel appears to be nylon

author: Fraser
author_rank: Super Contributor
timestamp: December 07, 2022, 07:09:57 pm
content: Well there you have it.... the interior of the HIKVISION DS-2TE127-G4A.I like what I see inside the unit and it is accurate but that does not surprise me as the OMRON PID controller is a pretty expensive unit to include in the BoM for the manufacturer. They could have used a far less expensive PID temperature controller costing <10% of the OMRON unit.... but that component is critical to the final accuracy and stability of the BlackBody so the OEM elected to use the quality product.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: December 07, 2022, 07:22:08 pm
content: Also of interest in this particular BlackBody is the OEM's use of a COTS Solid State Relay. In the DAHUA equivalent BlackBody, they designed their own "SSR" PCB rather than using a COTS component. This was presumably to save on the BoM cost. Once again, the HIKVISION unit uses a quality branded product for the SSR rather than a cheaper "no name" component that we commonly see in inexpensive equipment.Finally we can see that the HIKVISION unit incorporates a decent branded switch mode power supply in the form of the MeanWell LRS-50-24. MeanWell power supplies are a brand that I like to see in equipment as they are generally considered to be of decent design and build.I see no evidence of cost cutting in the HIKVISION DS-2TE127-G4A and its high cost may well be due to HIKVISION wishing to respond quickly to a market need and used good quality COTS components rather than trying to build their own modules or source cheaper alternatives.These compact and accurate reference Blackbody units are a direct result of the Global CoronaVirus Pandemic emergency management response and they are now appearing on eBay at far more affordable pricesThis unit cost £90 delivered and is in great condition with no damage to the emission plate coating and almost no dust inside. I suspect that it was a Demo unit due to its lack of dust inside and on the fan blades.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: December 07, 2022, 07:45:58 pm
content: The inside of a nicely made DAHUA Reference Blackbody may be seen here......https://www.eevblog.com/forum/thermal-imaging/danua-reference-blackbody-under-the-covers-)/msg4139053/#msg4139053To see what a "Cost Cut" Blackbody looks like take a look at my investigation of the BX-350. That BlackBody was poorly designed, used poor components and was, quite frankly, Junk ! I am rebuilding my unit to a better standard to make it of some use to me in my thermal camera repair work.https://www.eevblog.com/forum/thermal-imaging/bx-350-portable-blackbody-temperature-reference-teardown-by-fraser/msg4393027/#msg4393027Fraser

author: Fraser
author_rank: Super Contributor
timestamp: December 07, 2022, 10:29:35 pm
content: HIKVISION DS-2TE127-G4A BlackBody data sheet and manual....