The BTS-16110 regulates its internal temperature to maintain accuracy across its operating range. The input voltage and airflow environment affect the ability of the device to maintain accuracy.

Input Voltage

The power input voltage drives the heater circuits that maintain thermal regulation. When operating the BTS-16110 in a low-temperature environment, more heat is required to maintain temperature regulation.

Note When you deploy the BTS-16110 in an environment below 20 °C, you must provide at least 22.5 V input power for the device to maintain temperature regulation.

Airflow Environment

High airflow can lower the temperature around the BTS-16110, causing the heater circuit to require more power than it would in still air. This effect is especially pronounced if the BTS-16110 is operated at cold temperatures and the power input voltage is low.

The following figure shows how operation at cold temperatures and low input voltage affects the BTS-16110.

Figure 20. Airflow effects on the BTS-16110 operating range

Airflow effects on BTS-16110 operating range

Notice Never operate the BTS-16110 below 20 °C and 22.5 V, even in the natural convection state. As airflow over the BTS-16110 increases, the device may struggle to sufficiently compensate for the increased airflow at low temperatures and low voltages.

Example: Operation at 0-140 linear feet per minute (LFM) airflow

A triangular zone of low temperature and low voltage is present when operating with airflow velocity between 0 LFM and 140 LFM, as the following figure shows.

Figure 21. Operation with airflow less than 140 LFM

Operation with airflow less than 140 LFM

To maintain thermal regulation when operating in this environment, you must control the airflow.

The following figure shows the allowable airflow when operating in this triangle. When airflow increases, the minimum permissible ambient temperature rises.

Figure 22. Airflow effects on the BTS-16110 operating range

Airflow effects on BTS-16110 operating range

Guidelines for Controlling Airflow

NI recommends the following airflow control guidelines when operating the BTS-16110.

  1. Increase the input voltage.
    Higher voltage provides more power to the heater circuit and increases the effectiveness of the BTS-16110 thermal regulation circuit.
  2. Increase the temperature.
    The BTS-16110 thermal regulation circuit doesn’t work as hard at higher temperatures. To maximum the airflow when the temperature is high, use a fan controller that ramps with the ambient temperature.
  3. Block the airflow. You can use the following blocking methods to make the BTS-16110 heat up appropriately.
    • Obstruct the airflow.
    • Locate the BTS-16110 inside a box or housing.
    You can also rotate the BTS-16110 to decrease the effect of the airflow.

Test your System

System-specific effects like recirculation or proximity of neighboring components may affect airflow.

NI does not provide guidance when airflow is greater than 140 LFM. Monitor the temperature around the BTS-16110 to determine how the airflow in your system affects the BTS-16110. Follow the airflow control guidelines until you maintain thermal regulation across the entire operating domain.