What to Know About Monnit NIST-Traceable Sensors

Monnit offers NIST certificates, which certify the sensor’s accuracy within the time frame specified for the NIST certificate. Our calibration partner is accredited to provide official NIST certificates for the accuracy of the sensor. Details for these certificates are provided below.

1. NIST is the National Institute of Standards and Technology (not Testing).
2. NIST-traceable standards are reference materials certified to specific values laid out by NIST. They’re designed for standardized instrument calibration and quality assurance protocols to eliminate measurement uncertainties. NIST-traceable standards imply that all calibrations are part of an unbroken chain of comparisons from the manufacturer to the end-user.
3. NIST certification indicates that a device was tested against a NIST-traceable standard at a specific point in time and was found to be accurate, having passed the testing.
   1. This doesn’t guarantee that the sensor will be accurate after this point, even for the calibration interval.
   2. It is critically important that you recertify your sensors to complete the assurance loop.
   3. If a sensor is recertified and found to be out of tolerance, it was possibly out of calibration immediately after the initial passing calibration. This is unlikely, but still possible.
4. Within the NIST certification, it is important to use an accredited laboratory (ISO 17025).
   1. It’s possible to use NIST-traceable test equipment, but that doesn’t mean the test process is appropriate for calibration.

Standard Temperature Sensor (Non-Leaded)—25-Month Calibration Interval

3-Point Sweep (Standard)

Celsius:

Range 1 (-20°) (tolerance +/- 1°C)

Range 2 (20°) (tolerance +/- 1°C)

Range 3 (60°) (tolerance +/- 1°C)

Fahrenheit:

Range 1 (-4°) (tolerance +/- 1.8°F)

Range 2 (68°) (tolerance +/- 1.8°F)

Range 3 (140°) (tolerance +/- 1.8°F)

The sensor is first calibrated or adjusted at 20°C, and this single-point calibration adjusts the entire sensor range. The calibration will be rejected if the sensor does not pass each test point after calibration. If this is a recalibration, the customer will be informed of the failure

Standard Leaded (Submersible) Temperature Sensor—25-Month Calibration Interval

3-Point Sweep (Standard)

Celsius:

Range 1 (-25°) (tolerance +/- 1°C)

Range 2 (28°) (tolerance +/- 1°C)

Range 3 (90°) (tolerance +/- 1°C)

Fahrenheit:

Range 1 (-13°) (tolerance +/- 1.8°F)

Range 2 (82.4°) (tolerance +/- 1.8°F)

Range 3 (194°) (tolerance +/- 1.8°F)

The sensor is first calibrated or adjusted at 28°C, and this single-point calibration adjusts the entire sensor range. It is rejected if the sensor does not pass each test point after calibration. The customer will be informed of the failure if this is a recalibration.

Low Temperature Sensor—13-Month Calibration Interval

3-Point Sweep

Celsius:

Range 1 (0°) (+/- .5°C)

Range 2 (-80°) (+/- .8°C)

Range 3 (-196°) (+/- 1.5°C, liquid nitrogen bath)

Fahrenheit:

Range 1 (32°) (+/- .9°F)

Range 2 (-112°) (+/- 1.44°F)

Range 3 (-320.8°) (+/- 2.7 °F, liquid nitrogen bath)

The sensor is first calibrated or adjusted at 0°C, and this single-point calibration adjusts the entire sensor range. The calibration will be rejected if the sensor does not pass each test point after calibration. If this is a recalibration, the customer will be informed of the failure.

Humidity Sensor—7-Month Calibration Interval

3-Point Sweep

Celsius:

80% RH @ 20°C, 50% RH @ 30°C, and 20% RH @ 40°C

Relative Humidity Tolerance = +/- 5% RH, Temperature Tolerance = +/- 1°C

Fahrenheit:

80% RH @ 68°F, 50% RH @ 86°F, and 20% RH @ 104°F

Relative Humidity Tolerance = +/- 5% RH, Temperature Tolerance = +/- 1.8°F

If the sensor falls outside any of the above ranges, it can't be directly calibrated. However, the sensor can be repaired for a fee. If this is a recalibration, the customer will be informed of the failure.