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  • Sentry Trip Amplifier (with LED display)

    With Simple Setup via USB

    Sentry Trip Amplifier (with LED display). Find out everything you need to know about the Define Instruments Sentry (2 x Relay Outputs) in just 30 seconds with our quick video overview.
    Sentry (2 x Relay Outputs)

    CUSTOMIZABLE PRODUCT: This product is available in custom configurations for OEMs and high volume orders (over 100 pieces). If you have a difficult application that requires our engineering input, please call 1-888-652-4757 so we can assist you.

    Output Options (Please Select)
    • Bridge Key - $

      Universal USB Communications Kit

        Out of stock. Pre-order available.

    What it does:
    The Sentry accepts one of several popular input signal types and offers two relay outputs for alarming.

    The Swiss Army knife of trip amplifiers!

    If you're looking for the right tool for your monitoring and alarm application, the Sentry is it. This din rail mountable unit measures just 0.91" and provides maximum flexibility.

    Works with both AC or DC voltage

    No need to worry about what power is available in the field, you can plug the Sentry into whatever there is: Mains, 24V, whatever! No stress about stocking high and low voltage versions or whether you've taken the right one with you to the job. The Sentry is a truly universal unit, so you can relax!

    Huge range of input types

    The Sentry accepts 7 signal input types: Potentiometer, V, Tc, mA, Freq, NTC and RTD. This guarantees that whatever signal you've got to measure, you can do it with the Sentry.

    “I was extremely impressed with the wide range of features and input signals The Sentry trip amplifier is capable of. The price makes it the best in class value on the industrial market. It was easy to configure too.”
    Chris Carda, President, Criterion Industrial

    Optional display for easy to set up and troubleshooting

    A unique and distinguishing feature of the Sentry is it’s 4 digit display, making commissioning and fault finding easy. But if you prefer a more cost-effective unit without an LED display, one is also available.

    60 second set up

    It doesn't get any easier than this. You'll set it up in a flash using our free ToolBox software.

    In addition to this software a Bridge Key is required for the configuration of this product. You must order one unless you already have one from a previous product purchase.

    Compare trip amplifiers

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    Relays Price
    Acromag 801A-001-C
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    Datexel DAT5028
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    Omega DMD1080
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    Red Lion IAMS0010
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    Prices checked Feb 28, 2017

    The Sentry Trip Amplifier can be used for a myriad of control and alarm applications, and will also be at home in the signal conditioning arena. It accepts analog inputs from a range of industrial sensors, including: process, temperature, flow, frequency, and voltage from 200mV to 300V. It features a wide range power supply that suits both AC mains and 24V DC applications, and supplies the excitation required for common sensors and transmitters.

    The Sentry comes standard with two relays, which can be set up for a variety of alarm and control functions. An optional isolated analog output provides both 0(4)–20mA and 0–10V signals to interface to PLC's and SCADA systems.

    The Sentry is a tough and reliable instrument that has been designed for demanding industrial environments. Advanced techniques have been used to meet or exceed CE noise immunity requirements.

    The unit also has a 4 digit display for your convenience during commissioning, and to simplify fault-finding in the event of a system malfunction.

    Universal input:

    • Temperature input
      Thermocouple (B/E/J/K/N/R/S/T types), RTD (Pt100/Pt1000), NTC (10K Beta 3984/3435)
    • Process input
      Current (0/4–20.000mA DC), Voltage (various ranges from -10V to 300V DC)
    • Digital input
      NPN/PNP open collector (0–2000.0Hz)
    • Potentiometer input (<1kΩ to 20kΩ)
    • AC current sensor input (ACCS-010/ACCS-420(-L))

    Other features:

    • Universal AC/DC power supply (24-250V AC, 19.5-250V DC) – no header adjustments required!
    • 2 x relay outputs (1 Form A and 1 Form C) - ideal for alarming and on/off control
    • Optional isolated 0(4)–20mA or 0-10V output, making the Sentry ideal for use as a PLC/SCADA accessory
    • 22V excitation to power two wire transmitters
    • Flexible 32 point linearization table

    Easy, USB Powered Programming

    Simple & Flexible Input/Output Setup The unit boasts a 1 minute setup time using the Define ToolBox configuration software. All functions and features are explained expertly in the dynamic sidebar help - perfect for the novice starting out who can use it to learn about industrial sensors and applications, or the expert who wants to save commissioning time.

    Universal Input
    Number of universal inputs
    Accepts Thermocouple, RTD, NTC, Current, Voltage, Digital Pulse, Potentiometer & AC Current sensor
    (See below for full specifications for each input type)
    Power supply
    24-250V AC / 19.5-250V DC, 47-63Hz, 6VA max
    2,300Vrms for 1min to all inputs and outputs
    Thermocouple Input
    Thermocouple types

    K: -328 to 2502°F (-200 to 1372°C)
    B: 752 to 3272°F (400 to 1800°C)
    E: -328 to 1472°F (-200 to 800°C)
    J: -328 to 1832°F (-200 to 1000°C)
    R: -58 to 3200°F (-50 to 1760°C)
    S: -58 to 3200°F (-50 to 1760°C)
    T: -328 to 752°F (-200 to 400°C)
    N: -328 to 2372°F (-200 to 1300°C)
    Input impedance
    1MΩ min
    T/C lead resistance
    100Ω max
    Cold junction compensation
    -14 to 158°F (-10 to 70°C)
    CJC error
    < ±1°C
    E, J, K, N, T: < ±1°C. B, R, S: < ±2°C.
    Ambient drift
    E, J, K, N, T: < ±0.05°C/C. B, R, S: < ±0.2°C/C.
    Sensor break output drive
    Function high upscale/low downscale
    Response time
    RTD Input
    RTD input type
    PT100 or PT1000 DIN 3-wire type (2-wire can be used with off set trim)
    Lead wire resistance

    PT100: 50Ω/wire max. 0.02% FSO off set error per Ω of lead resistance mismatch
    PT1000: 20Ω/wire max. 0.002% FSO off set error per Ω of lead resistance mismatch
    Sensor current
    0.3mA nominal
    Sensor break output drive
    Function high upscale/low downscale
    Better than 0.2°C
    Ambient drift
    <0.007°c dd>
    Response time
    NTC Input
    10K Beta 3984: -67 to 257°F (-55 to 125°C)
    10K Beta 3435: -58 to 230°F (-50 to 110°C)
    Response time
    Better than 0.4°C
    Ambient drift
    <50ppm dd>
    Current Input
    +22V DC, 25mA max
    USB programmable zero
    0–±99% of span
    Field programmable span
    1μA–24mA DC
    Input impedance
    Max over-range
    50mA DC continuous
    Linearity & repeatability
    <±0.02% fso dd>
    Ambient drift
    <50ppm dd>
    Response time
    Voltage Input
    Millivolts: ±200mV, –200mV to 1V
    Volts: 0–10V, ±10V, –10 to 30V, 0–300V
    USB programmable zero
    0–±99% of span
    USB programmable span
    95% of FSO
    Input impedance
    1MΩ min
    Linearity & repeatability
    0–10V: <±0.05% fso
    0–300V: <±0.1% fso. all other ranges: <±0.02% fso dd>
    Ambient drift
    <50ppm dd>
    Response time
    Digital Pulse Input
    Frequency range
    Open collector (NPN, PNP)
    +22V DC, 25mA max
    Response time
    Software modes
    General frequency, Flow rate (pulse), or RPM (pulse)
    Linearity & repeatability
    Ambient drift
    <50ppm dd>
    AC Current Sensor Input
    Sensor type
    Current transformer (ACCS-420(-L)/ACCS-010)
    Amperage range
    Header selectable
    ACCS-420/010 = 100/150/200A
    ACCS-420-L = 10/20/50A
    ACCS-420/010 = 175/300/400A respectively
    ACCS-420-L = 80/120/200A respectively
    (Representing 0–100% of full scale input range) ACCS-420 = 4–20mA DC loop powered
    ACCS-010 = 0–10V DC
    Power supply
    ACCS-420(-L) = Loop powered, 15–36V DC
    ACCS-010 = Self powered
    1% of full scale
    Response time
    250ms (10–90%)
    Isolation voltage
    Potentiometer Input
    Potentiometer input
    Excitation voltage
    <1kω low pot; 1–4kω med pot; 4–20kω high dd>
    Potentiometer resistance
    Field programmable zero
    0–90% of span
    Field programmable span
    Linearity & repeatability
    <±0.05% fso dd>
    Response time
    Ambient drift
    <50ppm dd>
    Relay Output
    Number of relay outputs
    Relay output type
    1 x Form C, 1 x Form A
    Isolation to sensor and user input commons: 2,300Vrms for 1min. Working voltage 240Vrms
    Contact rating
    Form C relay: 10A @ 120/240V AC or 28V DC (resistive load)
    Form A relay: 3A @ 120/240V AC or 28V DC (resistive load)
    Life expectancy
    100K cycles min at full load rating
    Analog Output (Retransmission)
    Number of analog outputs
    1 (R2A model)
    Analog output type
    Self-powered (active) 0(4)–20mA or 0–10V DC (software selectable)
    Isolated to sensor and user input commons
    Isolation test voltage
    1,400Vrms for 1min. Working voltage 125V.
    0.05% of FSO
    0(4)-20mA = 1µA, 0-10V = 1mV
    Max output drive
    20mA (600Ω max load at 12V DC)
    User Input
    Number of user inputs
    1. Can be programmed for manual relay reset, latching, or zero functions
    Max continuous input
    20V DC
    User input isolation
    Not isolated to sensor input common
    Define ToolBox
    USB programmable using Define ToolBox (Bridge Key required)
    Display type
    0.4" (10mm) red LED, 7-segment characters
    LED indicators
    2 x setpoint indicator LEDs
    Full scale range
    -1999 to 9999
    Installation Category II, Pollution Degree 2, Flame resistant. Plastic flap to protect front display. (Swing upward to access programming port)
    Ingress protection rating
    IP20 rated - Install in a protective enclosure
    Dimensions (H x W x D)
    3.98 x 0.91 x 4.72" (101 x 23 x 120mm)
    Approx 177g (6.2oz), including plugs
    35mm DIN rail mount
    Environmental Conditions
    Operating temperature
    14 to 122°F (-10 to 50°C)
    Storage temperature
    -4 to 140°F (-20 to 60°C)
    Operating humidity
    5-85%RH max (non-condensing)
    Up to 2,187yd (2,000m)
    Certifications & Compliances
    EN 61326-1
    Immunity to Industrial Locations
    CISPR 11 Class A (EN 61326)
    Safety requirements for electrical equipment for measurement control and laboratory use
    EN 61010-1 General Requirements, EN 61010-2-030 Particular Requirements for Testing and Measuring Circuits

    Sentry Manual Sentry Manual 17V01, 01-Aug-2017 | (2100 KB)

    Sentry Datasheet Sentry Datasheet 17V01, 01-Aug-2017 | (372 KB)

    Define ToolBox

    Define ToolBox

    Smart, simple software to program your non-Zen series products

    Use Define ToolBox software to program your non-Zen series product via your PC. It configures:

    It offers a simple interface for connecting to your compatible device, and a range of flexible configuration options, including an extensive library of pre-calibrated ranges and linearization tables for advanced scaling.

    -UV 24-250V AC / 19.5-250V DC
    -R2 2 x relay outputs (PLUS 1 x User input for relay reset or latching)
    -R2A 2 x relay outputs (PLUS 1 x User input for relay reset or latching)
    1 x 0(4)-20mA or 0-10V analog output (software selectable)
    -R2-ND 2 x relay outputs (PLUS 1 x User input for relay reset or latching)
    1 x 0(4)-20mA or 0-10V analog output (software selectable) No LCD display
    -R2A-ND 2 x relay outputs (PLUS 1 x User input for relay reset or latching)
    1 x 0(4)-20mA or 0-10V analog output (software selectable) No LCD display
    Sample order codes: SEN-UV-R2, SEN-UV-R2A, SEN-UV-R2A-ND
    Sentry (2 x Relay Outputs)

All prices are in US Dollars. For pricing in other currencies, please contact us.