Analog Engine Tachometer
AR-7240B (Auto Range Type)
The AR-7240B is an analog engine tachometer featuring the automatic full scale switching function. When engine rotation is measured in the low scale, such as idling speed adjustment, it can be observed in the low range with 200 r/min scale. And the meter scale can be switched automatically to the high range with 10,000 r/min scale when engine rotation is increasing up into high speed load domain.
For gasoline engine measurement, the IP ignition pulse detector (for primary or secondary side) can be set up byseries one-touch attachment. For diesel engine, the VP-202/VP-1220 detector can be used. In addition to AC power supply, optional DC power supply is available and enables the AR-7240B on-board use or any place to measure. The analog output helps to figure out fluctuation of rotation speed, and pulse output can be applied to process the number or cumulated rotations of ignitions.
Features
Overview Specification
| Applicable detectors (option) | IP-292/296/3000A/3100, OM-1500/1200, VP-202/1220, MP-9100/981, LG-916, TTL |
|---|---|
| Measurement range | 400 to 10,000 r/min (The upper limit of rotation depends on a detector and setup of input pulse switching.) |
| Input pulse switching | 0.5 to 199.5 P/R (in 0.5 P/R steps, depending on a detector) |
| Trigger level | IP-292/296/3000A/3100, OM-1200,
VP-202/1220:settable using dial-type potentiometer MP-9100/981, LG-916, TTL:internally adjusted and fixed |
| Meter | 110mm square wide angle meter (low/high/automatic switching)) |
| Measurement scale | 0 to 2,000 r/min (red) 20 r/min per 1 scale 0 to 10,000 r/min (black) 100 r/min per 1 scale |
| Analog voltage output ＊ | 0 to 5 V / 0 to 10,000 r/min (Can be changed to 0
to 1 V / 0 to 10,000 r/min as an option.) Load resistance: 1 kΩ Linearity: ±0.5% / F.S. max. Output adjustment range: ±4% /F.S. max. (zero), ±4%/F.S. max. (span) response time: approx. 80 ms or less/10 to 90% (when no signal input, the response will delay by 3 to 4 seconds. |
| Pulse output | 1 P/R, 60 P/R (asynchronous to the input
signal)or wave-shaped output of the input signal TTL level, fanout 2 |
| Contact output | Run judge: 1 to 99 × 100 r/min Overrun: 1 to 99 × 100 r/min Comparison interval; every 100 ms Transfer contact, contact capacity: resistant load 240 VAC / 2 A , 30 VDC / 2 A |
| Power requirement | 100 to 240 VAC ± 10%, approx. 25 VA (option: DC 11 to 15 VDC, approx. 13 VA) |
| Operating temperature range | 0 to +40 °C |
| Outer dimensions | 210 (W) × 149 (H) × 300 (D) mm |
| Weight | Approx. 4 kg |
| Accessories | ・AC power cable (1.9 m), fuse |
＊Current output can be optionally modified (0 to 10mA/0 to 10000r/min).
(The voltage output is not available when the current output is provided.)
Revised:2011/02/01
