Applied Microsystems' temperature sensors are constructed of a precision aged thermistor bead, housed in stainless steel capillary tubes.  The time response of the sensor is governed by the capillary tube and varies from 100 milliseconds tp 1 second. 

Every temperature sensor is driven with an alternating potential to eliminate any parasitic thermocouples and amplifier offsets.  The temperature signal is AC coupled to an amplifier and synchronously demodulated to a steady state level.

In general, Applied Microsystems offers three types of temperature sensors.  The primary differentiator between the three sensors is the response time of the sensor.  Physically, temperature sensors with faster response times tend to have narrower capillary tubes (see photos below) to enable a faster transmission of temperature change to the thermistor.

Applied Microsystems Temperature Sensor Choices

Sensor	Application Fit	Photo
100ms	High speed profiling; applications requiring calculations of density, salinity, or sound velocity
500ms	Slow profiling applications requiring sensor robustness, sea chest applications, in-situ applications.
1000ms (1 second)	In-situ applications with minimal expectation of temperature change and maximum robustness requirements.

Temperature accuracies, precisions, resolution and response time vary by sensor type.  The following table summarizes the characteristics of each sensor.

Specifications by Sensor Type

Sensor Type	Accuracy (°C)	Precision (°C)	Response (ms)	Resolution (°C)
100 ms	+/- 0.005	+/- 0.003	100 ms	0.001
500 ms	+/- 0.005	+/- 0.003	500 ms	0.001
1000 ms	+/- 0.050	+/- 0.003	1000 ms	0.001

Many vendors of oceanographic instrumentation refer to accuracy and precision interchangeably.  They are not interchangeable.  In effect, accuracy refers to how well a sensor performs against a known third party standard.  For example, a temperature sensor may be +/- 0.001 C, as compared to a Black Stack themistor module.  Precision refers to the repeatability of the readings of a given sensor.   A sensor is precise when it repeatedly provides the same reading, regardless of how accurate that reading is.

A good analogy is a dart board.  The thrower of darts is accurate when he or she is able to reach the target, the bulls-eye.  He or she is precise if, having thrown three darts, all three land in the same location, irrespective of whether or not that location is the bulls-eye.

For a detailed explanation of how we calibrate Applied Microsystems' temperature sensors - including a listing of Frequently Asked Questions - please click here.

Applied Microsystems designs and manufactures sensors - conductivity, temperature and pressure - that have unusually fast response times.  Rapid response times are important in a wide variety of scenarios.  However, if you intend to do vertical profiling - where accurate mapping of the thermocline or picnocline is important - or if you plan to calculate salinity or density - where mismatches between sensor readings can generate spiking, then rapid sensor response times should be a critical decision factor in your choice of supplier.