the comet turnbuckle load-cell has been designed to measure the static tension within hanger rods and tie rods where the external forces applied to restrained equipment have to be accurately set or monitored.
the unique design of the load-cell allows for very accurate setting and measurement of the tension within the restraining member. by physically measuring the set gap between the ends of the threaded rods using callipers or a vernier, the load-cell can be replaced with a conventional forged turnbuckle with confidence in the knowledge that optimum force has been set. supplied with full certification against nationally accredited test equipment, the comet turnbuckle load-cell requires no maintenance but should be re-calibrated as necessary in accordance with local standards and requirements.
| size | rod diameter |
a (mm) |
b (mm) |
c (mm) |
d (mm) |
swl (kn) |
|---|---|---|---|---|---|---|
| 1 | 12 | 50 | 200 | 15 | 30 | 5 |
| 16 | 10 | |||||
| 2 | 20 | 60 | 210 | 15 | 40 | 15 |
| 24 | 20 | |||||
| 3 | 30 | 75 | 250 | 20 | 55 | 35 |
| 24 | 50 | |||||
| 4 | 42 | 100 | 300 | 30 | 75 | 75 |
| 48 | 125 | |||||
| 56 | 150 | |||||
| 5 | 64 | 175 | 300 | 30 | 90 | 175 |
| mechanical: | ||
| material: | bs 970 : part 1 : 817m40t | |
| thread form: | bs 3643 class 7h isometric coarse (other forms available on request) | |
| finish: | zinc plated to bs 1704 fezn8 class 1 a | |
| safe service load: | 150% rated load | |
| ultimate load: | 400% rated load | |
| electrical: | ||
| excitation voltage: | 10v dc (maximum) | |
| output voltage: | 1.0 mv/v | |
| combined error: | < 0.5% rated load | |
| repeatability: | < 0.05% rated load | |
| output at zero load: | ± 2.0% rated load | |
| input resistance: | 350 ± 2.0 ohms | |
| output resistance: | 350 ± 2.0 ohms | |
| temperature range: | ||
| normal operating: | -20 to +60°c | |
| compensated range: | -10 to +50°c | |
| temperature coefficient: | < ± 0.01 %/°c of zero | |
| temperature coefficient: | < ± 0.01 %/°c of span | |
| environmental protection: | ip67 | |
| insulation at 100v dc: | >500m ohms |
options
two types of load-cell are available. the basic version is as specified above and relies upon a remote strain gauge amplifier to boost its output for display. this would typically be carried out by the instrumentation within the comet digital display and would be suitable for use in close proximity to the display where electrostatic interference is low.
when it is necessary to run long cable lengths from load-cell to display, and particularly where electrostatic interference is high, we recommend the load-cell be fitted with an integral amplifier to minimize the signal-to-noise ratio and reduce the possibility of erroneous data.
| span adjustment | 0.3 to 1 omv/v at full range |
| zero adjustment | ± 20% rated load |
to order comet turnbuckle load-cells, you need to specify the thread size, the operating load range and whether or not you require an on-board amplifier.
by using the following code we can be sure that we are supplying what you require:
| a | basic size of cell 1 to 5. |
| bbb | thread size: m24, etc. imperial sizes: give 1.5, etc, and add thread form after code. |
| ccc | maximum operating load: 75, etc. |
| d | 'a' for standard type; 'b' for type with integral amplifier. |
2/m24/020/a - specifies an m24 load-cell for 2okn for use with a standard amplifier display.
4/1 .75/075/b (bsw) - specifies a load-cell with an integral amplifier and tapped to suit a 1.75" bsw thread.
support equipment
to complement the comet turnbuckle load-cell we offer a range of compatible digital displays, electronically matched and calibrated to one or multiple load-cells.
the standard instrument is a 3.5 digit lcd display which is
powered by rechargeable nickel-cadmium batteries and is the
size of a large 'pocket calculator'. it is equipped with a strain
gauge amplifier, zero and span adjustment, and is supplied in a
carrying case complete with battery charger and 3 metres of
cable for connecting to the load-cell.the standard unit is set to display in kilo newton units, though, upon request, units can be supplied with kilograms displayed. when load-cells with integral amplifiers are being used, a 3.5 digit current meter is supplied to the same general specifications as the standard display, though cable lengths are supplied to individual requirements.
the connecting plug for both types of display is a binder: the mating half has part number 273-574e. these connectors meet the requirements of protection standard ip40, which accords to din standard 40 050.
other load-cell displays are available to suit individual requirements - our sales staff will be pleased to advise.