Wireless Sensor Converter for Strain Gauge Sensors, 0-20mA, 0-10V (T24-ACMi)

The smallest of our T24 radio telemetry modules provides high performance telemetry measurement electronics for strain gauge, pressure, load cell, linear displacement and other 4 wire bridge sensors. Also available as 0-10V voltage input or 0-20mA current input.

The standard internal antenna supplied offers up to 100m (325 ft) range in an open field site. Low power modes allow the module to ‘power down’ between transmissions or to ‘power off’ completely and can be controlled by other T24 products such as the handheld displays or base stations.

An optional battery pack can be chosen to power the T24-ACMm which uses 2 x AAA cells and can be connected via simple 2 part screw field terminals. Also offers the option to fit wired completion resistors allowing a strain input to be either full, half or quarter bridge input.

The high accuracy, low noise measurement electronics deliver high resolution, low drift results which can be user calibrated over 9 points to enable linearization and to deliver results in user definable engineering units. The results can be transmitted at rates up to 200 per second to other T24 devices such as handheld displays, analog outputs and base stations etc.

The module is configured and calibrated (either by applying known inputs or by table entry) using T24 Toolkit software which runs on a PC connected to a T24 base station.

The licence free 2.4GHz direct sequence spread spectrum (DSSS) radio technology offers high integrity, error free communications which can co-exist with other wireless technologies such as Wi-Fi, Bluetooth® and Zigbee®. FCC, ETSI and IC approvals.

The T24-ACMm-SA Strain version provides direct mV/V input and 5V bridge excitation for up to 4 load cells.

Also available in OEM PCB format.
 

T24- ACMi

Find out the battery life of your system using our Battery Life Calculator

* Check operating temperature batteries intended for use.

**Maximum range achieved in open field site with the T24 acquisition module at a height of 3 metres (9.8 feet) above ground and T24-HS held at chest height pointing towards the acquisition module. Specification at 3V supply at 25°C

 

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These are the following industries and applications in which this product has been used:

• Alternative Energy - Wireless Telemetry Strain Measurement of Wind Turbines
• Civil Engineering - Wireless Monitoring of Surrounding Buildings during Underground Excavation
• Civil Engineering - Bridge Bolt Monitoring
• Agriculture - Vessel Level Control & Flow Sensing

Q: What is the range of T24?

A: The T24-ACMm which has an integral antenna has a range of 100 metres direct line of sight. The T24-ACM / T24-ACMi uses a integrated PCB T24-ANTA antenna provides up to 200 metres range in ideal conditions. This range can be doubled using the T24-AR (Active repeater).

Q: What inputs are available to the T24 system?

A: The T24 system supports Strain, Current, Voltage, Temperature, Pulse and Potentiometer acquisition.

Q: How reliable are the readings?

A: Due to the digital nature of the T24 system, when a reading is received by any device it is guaranteed not have been distorted over the RF transmission.

Q: What software is provided with the T24 devices?

A: All devices are supported by the T24 Tool Kit which allows users to
configure all devices from the T24 range as well as view and log data from
acquisition modules in range. The software can also be downloaded directly
from our website.
 

Q: How many devices can operate on one radio channel?

A: Many devices can operate on the same radio channel depending on the sample rate of the acquisition modules present in the system. There are 16 channels available with each one capable of supporting up to 200 data packets per second.

Q: Can PC software gather data from many devices?

A: Yes, Mantracourt provides freeware for logging up to 24 inputs to one base station, in addition the open COM driver can be used to gather data through customers own PC software to applications in Visual Basic which in turn has been used to integrate the T24 system with Lab View.

Q: What limits the RF range of the devices?

A: Any metal surface will reflect 2.4 GHz radio waves, therefore in a sealed metal box, no RF will escape. However by providing a suitable RF window the signals will propagate out.

Q: What Frequency does the system operate on?

A: Licence free world wide 2.4GHz, although this frequency is used by other equipment the T24 range has been tested with Bluetooth, Zigbee & WiFi devices with out conflicts.

Q: Is it possible to use repeaters within T24 network?

A: The T24-AR Active repeater which can be added to the system can propagate a signal around corners and obstacles. This unit can also double the effective range.

Q: Is the system point to point?

A: Yes, however the modules may also operate in many to one (such as multiple data acquisition modules communicating with a base station) and one to many (such as a data acquisition module supplying data to multiple handhelds and displays).

Q: What sensors would these inputs cover?

A: Any sensor that provides a voltage, current or ratio metric interface can be connected to an acquisition module, including load cells, inclinometers, accelerometers, displacement LVDT, pressure, potentiometer, pulse, temperature, humidity, ph, shock.

Q: What is the communication protocol?

A: Proprietary protocol based on a 804.15.4 chip. This allows the T24 range to co-exist with Bluetooth, Zigbee & WiFi devices with out conflicts.

Q: What are the sampling rates of the acquisition modules?

A: The T24 standard acquisition modules (SA, IA, VA, RA, TA, PA) sample from 0-200 updates/sec. The T24-SA fast acquisition modules are fixed at 2,000 updates/sec.

Q: What is the resolution of the acquisition modules?

A: The noise free resolution for a sample time of 10 milli-seconds or less is 15.5 bits for the T24 SA, 12.5 bits for the T24-VA, 14 bits for the VA and 12.25 bits for the T24IA.

The T24-PA’s accuracy % input error @ 1 Hz is 0.15% and for the T24 RA the accuracy is 0.01% of the full scale.

With increased sample times resolution can be increased up to 18.75 bits for the T24-SA.
 

Q: What is the supply voltage for the acquisition modules?

A: 3V for the acquisition modules and handheld displays. Other modules in the range take 9-36 V.

Q: How are the modules powered?

A: The ACMm is the smallest module and has a separate battery pack (T24-BB1 using 2 x AAA). The T24-ACMi is the mid size module and provides power via 2 x AA batteries and has terminal block style field connectors for wiring to acquisition modules. The T24-ACM although larger can provide power from an external power supply (5-18V) as well as 2 x D cell batteries which provide a higher battery capacity allowing for longer battery life.

Find out the battery life of your system using our Battery Calculator.
 

 

Q: Can power be provided to a sensor?

A: Yes, all acquisition modules feature a 5V supply which is a excitation voltage (with exception of T24-RA which has 2.5V supply).

Q: How is the strain gauge acquisition module calibrated?

A: The modules are factory calibrated to 2.5 mV/V which can be custom calibrated and linearised over up to 9 points by using the T24 Toolkit. The T24-SAf has fixed factory calibration and cannot be linearised.

Q: What is the difference between the T24-SA and T24-SAf?

A: The standard acquisition modules are capable of providing data up to 200Hz. The ‘fast’ T24-SAf provides data at a fixed 2Khz.

Q: How many acquisition modules can be acquired by the base stations?

A: Each base station can use one of 16 channels. From one of those channels a base station can collect data simultaneously from any number acquisition modules depending upon the frequency of readings being provided by the acquisition module.

Q: What are the input ranges of the T24 acquisition modules?

A: T24-SA 2.5mV/V calibrated strain gauge based measurement; T24-VA 0-10V, T24-IA 4-20mA, T24-TA pt100 sensor input, T24-RA potentiometer 500 to 100000 Ohms and T24-PA 0.5Hz to 3kHz.