DIGITAL TACHOMETERS • Two types of digital read out, hand-held tachometers have been introduced to the market by Foundrometers.
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Model DT-2235 is a direct contact type. It is supplied with various adaptors designed to allow the shaft to pick up friction drive from virtually any object in rotating or linear mo
tion. Switch selection for rpm, ft/min or mirnin is provided on the case front panel. A drive contact time of one second maximum will produce a reading accurate to ±0.1rpm in the range 0.5 to 500rpm, or ±5% in the higher speed ranges up to 9,999rpm. The reading is maintained on the display by a memory with recall and erase facilities.
The second tachometer, Model DT-2232A, is a visible beam photo type. This unit does not require physical contact with the moving object. Instead, it is supplied with self-adhesive reflective markers for attachment to the object being monitored. The markers act as a target for the visible light beam and each time a marker passes through the beam a signal is generated to drive the read out. A stable reading is achieved in a sampling time of between half and 1.2 seconds and this reading i5 maintained on the display by a memory with recall and erase facilities. Accuracy is ±1rpm the range 50 to 9,999rpm or ±lOrpm in the range 10,000rpm and above. Automatic range adjustment initiates and indicates the x10 condition as speed exceeds 9,999rpm.
Each tachometer is individually bench tested and sold with a test certificate detailing actual accuracies achieved. They weigh only some 300gm (10oz) and are supplied with a carrying case making them suitable for engineers on the move.
Foundrometers Ltd South Accommodation Roa Leeds LS9 8LW