Load Sensor – There’S Certainly A Lot More Than What You Know Already Listed Here..

Field service engineers require many different load cells spanning the numerous ranges necessary to calibrate their customers’ systems. They might also require the assortment to conduct a wide range of force measurements for the testing application. The process begins once the engineer has to alter the load cell which is linked to his instrument before he could continue. If the new cell is connected to the instrument, the appropriate calibration factors have to be set up in the Force Transducer.

Avoiding user-error is a major challenge with manual data entry or with requiring the engineer to select from a database of stored calibration parameters. Loading a bad parameters, or even worse, corrupting the current calibration data, can lead to erroneous results and costly recalibration expenses. Instrumentation that automatically identifies the burden cell being attached to it and self-installing the proper calibration information is optimal.

What exactly is Transducer Electronic Datasheet? A Transducer Electronic Data Sheet (TEDS) stores transducer identification, calibration and correction data, and manufacturer-related information in a uniform manner. The IEEE Instrumentation and Measurement Society’s Sensor Technology Technical Committee developed the formats which include common, network-independent communication interfaces for connecting transducers to microprocessors and instrumentation systems.

With TEDS technology, data could be stored inside of a memory chip that is certainly installed inside of a TEDS-compliant load cell. The TEDS standard is complicated. It specifies a huge number of detailed electronic data templates with a few degree of standardization. Even when using the data templates, it is really not guaranteed that different vendors of TEDS-compliant systems will interpret what data is put into the electronic templates in the same manner. More importantly, it is really not apparent that the calibration data that is needed inside your application will likely be maintained by a particular vendor’s TEDS unit. You must also make certain you have a way to write the TEDS data to the TEDS-compatible load cell, through either a TEDS-compatible instrument which includes both TEDS-write and TEDS-read capabilities, or with the use of some other, likely computer based, TEDS data writing system.

For precision applications, such as calibration systems, it also need to be noted that calibration data that is kept in the load cell is the same no matter what instrument is connected to it. Additional compensation for that Rotary Torque Sensor is not included. Matched systems where a field service calibration group could be attaching different load cells to different instruments can present a difficulty.

Electro Standards Laboratories (ESL) has developed the TEDS-Tag auto identification system which retains the attractive feature of self identification found in the TEDS standard but could be implemented simply on any load cell and, when attached to the ESL Model 4215 smart meter or CellMite intelligent digital signal conditioner, becomes transparent towards the user. Multiple load-cell and multiple instrument matched pair calibrations are also supported. This can be a critical advantage in precision applications like field calibration services.

With the TEDS-Tag system, a little and cheap electronic identification chip is positioned in the cable that extends through the load cell or it can be mounted within the cell housing. This chip has a unique electronic serial number which can be read from the ESL Model 4215 or CellMite to distinguish the cell. The cell will be attached to the unit along with a standard calibration procedure is conducted. The instrument automatically stores the calibration data in the unit itself along with the unique load cell identification number through the microchip. Whenever that cell is reconnected to the instrument, it automatically recognizes the cell and self-installs the appropriate calibration data. True plug-and-play operation is achieved. With this particular system the calibration data can automatically include compensation for the particular instrument to ensure that high precision matched systems can be realized. Moreover, when the cell is transferred to another instrument, that instrument will recall the calibration data it has stored internally for your load cell. The ESL instruments can store multiple load cell calibration entries. In this way, multiple load cells can form a matched calibration set with multiple instruments.

Any load cell can be simply made into a TEDS-Tag cell. The electronic identification chip, Dallas Semiconductor part number DS2401, is easily provided by distributors or from ESL. The chip is extremely small, rendering it simple to match a cable hood or cell housing.

The ESL Model 4215 smart strain gauge indicator and the CellMite intelligent digital signal conditioner are connected to load cells using a DB9 connector with identical pin outs. The electronic identification chip does not interfere with the cell’s signals. Pin 3 of the DS2401 will not be used and can be shut down if desired. Simply connecting pins 1 and two through the DS2401 to pins 8 and 7, respectively, of the ESL DB9 connector will enable plug-and-play operation.

When you use off-the-shelf load cells, it is often convenient to locate the DS2401 in the hood from the cable. The cell includes a permanently mounted cable that protrudes through the cell housing. At the end of the cable, strip back the insulation from your individual wires and solder the wires into the DB9 connector. The DS2401 is soldered across DB9 pins 7 and 8, and fits in the connector’s hood. For a couple of dollars in parts as well as a simple cable termination procedure, you may have taken a standard load cell and transformed it right into a TEDS-Tag plug-and-play unit.

For applications in which accessibility load cell and cable is restricted, an in-line tag identification module could be simply constructed. A straight through in-line cable adapter can incorporate the DS2401 electronic tag chip. In this application, the cable adapter is actually put into series with the load cell cable before it is plugged into the Load Sensor. It is also possible to make use of this technique in applications where different calibrations could be required on the same load cell. The user may mbssap just one load cell and instrument, but could change which calibration is auto-selected by simply changing the in-line cable adapter. Since each cable adapter includes a different tag identification chip, the ESL instrument will associate an alternative calibration data set with every in-line adapter. This can be useful, as an example, if a precision 6-point linearization in the load cell is needed by two different operating ranges of the identical load cell.