METER TEMPOS Controller and Compatible Sensor Instructions
- June 6, 2024
- METER
Table of Contents
METER TEMPOS Controller and Compatible Sensor Instructions
INTRODUCTION
The TEMPOS controller and compatible sensors require accurate calibration and configuration to effectively measure thermal properties in materials. This troubleshooting guide is meant as a resource for METER Customer Support, Environmental Lab, and distributors to provide support for customers in using the device as designed. Support for TEMPOS and any associated Return Merchandise Authorizations (RMAs) will be handled by METER.
CALIBRATION
Does the TEMPOS need to be calibrated by METER?
Technically, no. The TEMPOS does not need to come back to METER on a regular schedule to get tuned up.
However, many customers need to get their equipment calibrated for legal requirements. For those customers METER offers a calibration service to check out the device and rerun verification readings.
If the customer desires to do this, create an RMA and use PN 40221 to bring it back to METER.
How much environmental variance (room temperature change, drafts, etc.) can TEMPOS tolerate before it impacts TEMPOS readings?
Any amount of thermal change in the environment surrounding the sample will impact readings. Minimizing temperature change and draft in the room and is important for all readings, but especially important in low conductivity materials like insulation.
Samples with a low thermal conductivity will be more impacted than those with a high conductivity because TEMPOS has a 10% margin of error for accuracy. Samples with a high conductivity (e.g., 2.00 W/[m • K]) can still be considered accurate across a wider margin for error (0.80 to 2.20 W/[m • K]) than a sample with a conductivity of only 0.02 (0.018 to 0.022 W/[m • K]).
I lost my calibration certificate. How can I get a new one?
Replacement calibration certificates can be obtained here: T:\AG\TEMPOS\Verification Certs
The certificates are organized under the serial number of the TEMPOS device, and then again under the serial number of the sensor. Both numbers will be needed to obtain the correct certificate.
EQUILIBRATION
How long does a sample need to equilibrate after inserting the needle?
This varies on the material. A good rule of thumb is that the more insulated the sample is, the longer it will take to reach thermal equilibrium. Soil may only need 2 min before taking a reading, but a section of insulation will need 15 min.
GENERAL
Are the TEMPOS and its sensors waterproof?
The TEMPOS handheld device is not waterproof.
The sensor cable and sensor head are waterproof, but METER does not currently have the ability to sell waterproof cable extensions for TEMPOS sensors.
Is there documented proof of TEMPOS specifications?
If a customer wants more data and documented information than what is listed on the METER website and in the sales presentation, direct their inquiries to the TEMPOS team, Bryan Wacker (bryan.wacker@metergroup.com) and Simon Nelson (simon.nelson@metergroup.com). They can provide papers written using the TEMPOS or KD2 Pro or other requested information.
How were range and accuracy determined?
Range was determined by extensive testing in materials at different levels of conductivity. The TEMPOS range of 0.02–2.00 W/(m • K) is a fairly large range of conductivity that covers most materials that researchers would be interested in measuring: insulation, soil, fluids, rock, food and drink, and snow and ice.
Accuracy was determined by using the glycerin standard that is shipped with the TEMPOS, which has a known conductivity of 0.285 W/(m • K). The hundreds of sensors built by the METER production team have been tested and all fall within 10% accuracy of that standard.
TAKING MEASUREMENTS
Why am I getting bad or inaccurate data in water or other fluids?
TEMPOS sensors can have a difficult time reading low-viscosity fluids due to the presence of free convection. Free convection is the process where fluid at the heat source warms up and has a lower density than thecolder fluid above, so the warm fluid rises and the colder fluid is pushed downward. This motion introduces an outside source of heat which will throw off the measurement being done by the TEMPOS sensor. Free convection is not a problem in high viscosity fluids such as honey or the glycerin standard, but it will cause real problems in water or other liquids around that level of viscosity.
Minimize all outside sources of heat and rattling or shaking as much as possible. Take readings with the water inside a styrofoam box in a still and quiet room. It is very difficult to get anywhere close to accurate thermal measurements in water if there is any machinery around, for example.
Can the TEMPOS sensors be used in a drying oven?
Yes, it can. Set the TEMPOS sensor in the drying oven on unattended mode during the drying process. This is much faster and easier than manually taking measurements while drying out a sample to create a thermal dryout curve.
This is a commonly asked question from customers hoping to use TEMPOS for ASTM soil measurements.
Why does the manual recommend using Soil mode over ASTM mode?
ASTM mode is less accurate because of its longer measurement time. Conductivity is temperature dependent, and ASTM mode heats and cools the soil for 10 min, compared with 1 min for Soil mode. Constant heat fluxes over 10 min mean that the soil becomes warmer than its native temperature, and therefore more thermally conductive. ASTM mode is included in TEMPOS despite this shortcoming to fulfill the requirements of ASTM.
Can the TEMPOS take readings in very thin materials?
TEMPOS is designed to have at least 5 mm of material in all directions from the needle to get an accurate reading. With very thin material, the TEMPOS needle will read not only the immediate material surrounding the sensor but also any secondary material beyond it within that 5 mm radius. The best solution to get accurate measurements is to sandwich several layers of the material together to achieve the appropriate measurement thickness.
Can we take a sample from the field back to the lab to measure?
Yes, TEMPOS was designed to work well in the field, but collecting samples and bringing them back to the lab for readings is also an option. However, consider how this may impact the moisture content of the sample. Any field samples need to be air sealed until they are ready to be measured because a change in moisture content will alter the result.
Can TEMPOS be used in my unique or uncommon application?
The answer depends on three factors:
-
Conductivity.
TEMPOS is rated to make accurate measurements from 0.02 to 2.0 W/(m • K). Outside of that range, it is possible TEMPOS can perform at a level of accuracy that may satisfy the customer. -
Operating temperature.
TEMPOS is rated to work in environments of –50 to 150°C. If the temperature is significantly higher than that, parts on the sensor head can melt. -
Contact resistance.
TEMPOS sensor needles need to be in contact, or at least close to it, with the material to get a good reading. Fluids and very small granular materials allow this to happen easily. More rigid surfaces, like rock or concrete, are difficult to get good contact between the needle and the material. Poor contact means the needle is measuring air gaps between the material and the needle and not the material itself.
If customers have concerns with these factors, METER recommends sending a sample to METER for testing before selling them a device outright.
TROUBLESHOOTING
Problem
|
Possible Solutions
---|---
Cannot download data using TEMPOS Utility|
-
Verify the latest version of TEMPOS Utility is being used
(metergroup.com/tempos-support). -
If using the most recent version of TEMPOS Utility does not solve the issue, create an RMA to return the device to METER for repairs.
TEMPOS will not turn on or is stuck on black screen|
- Open the back of the device and remove the batteries to force a power-off state.
- Replace the batteries and the back panel.
- Hold down the POWER button for 5 s to reboot the device.
- If that does not work, create an RMA to return the device to METER for repairs.
SH-3 needles bent or poorly spaced| Slowly and gently push the needles back
into their proper place manually. (If the needles are bent too quickly or too
much, the heating element within the needle will break.) A red SH-3 needle
spacing tool shipped with the TEMPOS provides a guide for proper spacing (6
mm).
Temperature changes during reading|
- This is common in Unattended mode if taking many readings over a long period of time.
- Ensure the sample and the needle are stationary. Bumping or jostling the sample or the sensor will cause a temperature drift.
- Avoid any rumbling or rattling that can throw off a reading, especially in fluids.
- Avoid reading next to computer fans, a room near the HVAC system, or any other situation that would add any extra movement.
- Remove or avoid extra sources of heat to ensure the room is the same temperature the whole time. If taking readings overnight, ensure the heating system does not turn on or off and change the temperature in the room.
- Avoid setting the sample in a location where it will be exposed to sunlight.
Obviously wrong or inaccurate data|
- There is a good chance that something is wrong with either the heating element or the temperature sensor within the needle.
- Check the screen during a reading, and verify red bars display on the screen. If no bars appear, then it is likely that the heating element has failed.
- Verify the reading returns temperature data. If no temperature data is returned then it is likely that the temperature sensor has failed.
- If either of these scenarios occurs, send the sensor to METER via an RMA.
- If the device does show red bars and returns temperature data but is still
giving bad data, return the whole device to METER via an RMA for further investigation.
SUPPORT
METER Group, Inc. USA
Address: 2365 NE Hopkins Court, Pullman, WA 99163
Tel: +1.509.332.2756
Fax: +1.509.332.5158
Email: info@metergroup.com
Web: metergroup.com
References
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>