Dry Contact, Voltage, Current, Resistive Bridge
Dry Contact General Description
ALTA Wireless Dry Contact Sensors can be used to detect contact between two wired contact points, an external mechanical switch, or a contact plate.
Key Features
Cable length:
- 0.3 m (1') Standard
- 0.9 m (3') O
Cable terminations: bare-wire
Can integrate with switches
Principles of Operation
The ALTA Wireless Dry Contact Sensor detects when there is contact between the two wired end points. It can easily be integrated into existing switches or contact plates. When the sensor detects contact between the two end points a wireless communication is immediately sent to the gateway. The gateway will immediately attempt to securely send the message to iMonnit, or other approved data services.
The sensor can be configured to detect both closed and open loops, alerting if contact is made or broken and on state changes.
Voltage General Description
The ALTA Wireless Voltage Meter measures DC voltage up to 5V or 10V on user specified intervals.
Key Features
Measurement Range: 0 to 5 VDC or 0 to 10 VDC
Resolution: 1 mV
Accuracy:
- Uncalibrated: ± 2.0% of reading ± 0.002 VDC
- Calibrated: ± 0.5% of reading ± 0.002 VDC
Configurable thresholds for critical condition monitoring
Principles of Operation
The ALTA Wireless 5 and 10 VDC Voltage Meter measures the single-ended DC voltage across its two leads based on a user-configurable time interval or Heartbeat. On every Heartbeat, the sensor converts the analog voltage signal to a digital voltage measurement. This measurement is then sent to the gateway, making the data available in iMonnit or another approved data service. The ALTA 5 and 10 VDC Voltage Meter can be calibrated for improved accuracy. Also, remember to remove any active voltages from the measurement leads when replacing batteries or performing other maintenance.
Current General Description
The ALTA® Wireless 0?20 mA Current Meter is capable of measuring the current from transducers with a 4 to 20 mA DC output. Both 2-wire and 3-wire current loop transducers are supported.
Key Features
Measures current up to 20 mA
Resolution: 0.001 mA
Accuracy:
- Uncalibrated: 0.01 mA (typical)
- Calibrated: 0.002 mA
Measurement resistor: 73.2 Ohms
Configurable thresholds for condition monitoring
Principles of Operation
The ALTA Wireless 0?20 mA Current Meter measures the DC loop current based on a user-configurable time interval or Heartbeat. On every Heartbeat, the sensor converts the analog current signal to a digital current measurement. This measurement is then sent to the gateway, making the data available in iMonnit or another approved data service. The ALTA 0?20 mA Current Meter can be calibrated for improved accuracy. Also, remember to remove any active current from the measurement leads when replacing batteries or performing other maintenance.
Resistive Bridge General Description
The ALTA Wireless Resistive Bridge Meter is a precision analog device that supplies an excitation voltage to a resistive bridge. It measures the voltage across the leads and reports this measured voltage in millivolts per volt (mV/V).
Key Features
Supplies up to 2.0V excitation
Resolution: 24-bit or down to 0.00001 mV/V
Accuracy: down to 0.0002 mV/V
Measures both positive and negative percentages
Programmable gain: 1X to 128X
Optional 50 Hz and 60 Hz filters
Cable length: 0.9 m (3')
Cable terminations: bare-wire
Reports additional temperature measurement
Principles of Operation
The ALTA Wireless Resistive Bridge Meter uses two wires, red(1) and black(4), to excite a resistor bridge, thus providing a reference voltage for the measurement. Two additional wires, white(2) and yellow(3), measure the differential voltage across this bridge in mV/V.
This meter contains a Programmable Gain Amplifier (PGA) and can be set to values between 1X and 128X, essentially increasing the measurement's resolution and reducing measurement error. The 50 and 60 Hz filters are also programmable.
Thresholds can be set so that when the output gets above or below a user-defined threshold, a wireless communication is immediately sent to the gateway. The gateway will immediately attempt to securely send the message to iMonnit or other approved data services
Features of Monnit ALTA Sensors
Wireless range of 2,000+ feet through 18+ walls1
Frequency-Hopping Spread Spectrum (FHSS)
Best-in-class interference immunity
Best-in-class power management for longer battery life2
Encrypt-RF® Security (Diffie-Hellman Key Exchange + Advanced Encryption Standard (AES)-128 Cipher Block Chaining (CBC) for sensor data messages)
Sensor logs 2000 to 4000 readings if the gateway connection is lost (non-volatile flash, persists through power cycling):
10-minute Heartbeats = ~ 22 days
2-hour Heartbeats = ~ 266 days
Automatic over-the-air updates to sensor firmware (future-proof)
Free iMonnit Basic Online Wireless Sensor Monitoring and Notification System to configure sensors, view data, and send alerts via SMS text, email, and voice call
1 Actual range may vary depending on the environment and gateway.
2 Battery life is determined by the sensor reporting frequency and other variables. Other power options are also available
>>Datasheet (Dry Contact)
>>Datasheet (5x Dry Contact)
>>Datasheet (Voltage)
>>Datasheet (Current)
>>Datasheet (Resistive Bridge)
