Rated 4.9 (120 reviews)
The Sentry Lite is the cut-down version of Formula Sound's Sentry MK2, for venues that need one fixed limit and nothing more. The wall-mounted display unit has a built-in microphone and an LED bar that shows how close the room is to the limit; if the level stays over it for the set time, the unit trips the supplied 32A contactor and cuts mains to the music equipment until it is reset. It comes as a complete kit with the contactor, so there is nothing else to specify for a single ring, and the settings sit under a sealed cover once the level has been agreed with the council.
70-120 dB
Threshold · Single level
32A
Contactor · Included
8 LED
Display · 23 dB span
Lin / Bass
Weighting · Jumper
Power the Sentry Lite separatelyThe display unit must be fed from a supply that the contactor does not control, otherwise it switches itself off when it trips. Formula Sound specify using only the contactor supplied, fitted by a qualified electrician to BS 7671. For two separate rings, the 153 version with a double contactor is available to order.
Features
Complete kit: display unit plus single 32A contactor
Built-in electret microphone, or an external mic with 18 V phantom power
One threshold level, 70 to 120 dB, set on a 10-turn potentiometer
Linear or Bass weighting (300 Hz low-pass) to target low-frequency complaints
8-segment LED display with WARNING and OVER LIMIT stages
Manual reset; powers up tripped so a power cut cannot bypass it
Microphone tamper and security loop LEDs
Settings under a screwed cover with non-reusable security labels
Remote WARNING and RESET REQUIRED outputs and remote reset input
Front-panel reset can be disabled so only the 074K or 074P remote box resets it
Low-voltage 2-core link to the contactor, bell wire is fine
Specifications
| Type | Cut-off sound level limiter (mains disconnect) |
| Threshold range | 70 to 120 dB, single level (+6 dB gain jumper below 90 dB) |
| Trip delay | Adjustable, factory set to 20 seconds |
| Weighting | Linear or Bass (300 Hz low-pass, 12 dB/octave) |
| Display | 8 LED segments: -20, -10, -5, -3, -1, +1, WARNING +2, OVER LIMIT +3 dB |
| Microphone | Internal electret; external mic input with 18 V phantom (jumper) |
| Contactor | Single 32A, single phase, fused (included) |
| Reset | Manual, local or remote |
| Power | 240 V AC approx. 1 A (110 V to order) |
| Enclosure | Polycarbonate UL94-V2, grey with clear cover, 3-screw wall fixing |
| Dimensions | Display unit 166 x 160 x 134 mm; contactor box 260 x 155 x 85 mm |
| In the box | Sentry Lite display unit, single 32A contactor, security labels |
| Part number | 152 |
