10k NTC Thermistor - Not Reading Resistance Properly?

@ideal2545 wrote:

Hi All,

So I have a 10KOhm thermistor, that I have in series with a 10KOhm 1% resistor. I have the datasheet which effectively states the the B_Constant is 3997 @ 1%. I have verified that the resistance on the thermistor is 10Kohm with my multimeter and also double checked the resistor I’m using to verify that its 10K Ohms.

I should be getting 25C at 10K ohms with this setup is my understanding but I am nowhere near that, at 22.7C I’m basically at 1965Ohms. (not to be confused with KOhms) So I’m very far off. This is how my YAML is configured currently:

sensor:
  - platform: ntc
    sensor: resistance_sensor
    calibration:
      b_constant: 3997
      reference_temperature: 25°C
      reference_resistance: 10kOhm
    name: NTC Temperature B Constant

  - platform: resistance
    id: resistance_sensor
    sensor: source_sensor
    configuration: DOWNSTREAM
    resistor: 10kOhm
    name: Resistance Sensor

  - platform: adc
    id: source_sensor
    pin: A0
    update_interval: 5s

I’m basically wired up like this, except i’m using 3.3V and A0 on an Amica NodeMCU ESP8266

698×359 113 KB

Here’s the breadboard view (red/white wires are heading to the thermistor).

IMG_25131536×2048 658 KB

Any help is really appreciated.

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