Senmatic's EC & pH alarm EPA904

EPA904 EC and pH Alarm

Get alarms when the set limits for EC and pH are exceeded

This standalone EC and pH alarm unit measures EC and pH and emits an alarm when the set limits are exceeded. Multiple uses include using the alarm in an irrigation system or for measurement of basin water. Four separate alarms can be set for minimum and maximum EC and minimum and maximum pH alarm respectively.

Extra security
Used together with a fertilizer mixer, you have additional security with this standalone EC and pH alarm. EC and pH will now be measured not only by the electrodes from the mixer, but also by the alarm.

Readout on scale
Quickly read the actual EC and pH level in the irrigation water directly from the scale on the box.

Easy to set
Setting the alarm levels is done easily using the buttons on the front of the box. Whenever an alarm occurs, a diode for the actual alarm will light up next to the knob with the setting.

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What's in it for you? ...... see below

Alarm unit for measuring EC and pH values

Alarm at exceeded max. and min. values

Readings diectly from the unit

Easy to set

Further functions Download product sheet Technical specifications
Further functions

Further essential functions

  • Four separate alarms
  • Extra security
  • Readout on scale
  • More accessories
Download product sheet

Download product sheet

Technical specifications



  • Supply: 24 VAC ±10 % 50/60 Hz - 400 mA
  • Alarm output: Potential free contacts max. 42 V - 2 A
  • Output EC: 0.3 - 4.5 V = 0 - 14 mS
  • Output pH: 0.3 - 4.5 V = 0 - 14 pH
  • Input EC: 2 point / 4 point EC electrode
  • Input pH: Standard pH electrode


  • Temperature: 0 - 50° C (32 - 122° F) without direct radiation
  • Humidity: 0 - 95 % RH without condensation
  • Dimensions H x W x D: 200 x 300 x 100 mm (7.8 x 11.8 x 3.9")
  • Weight: 2 kg (4 lb)
  • Protection: IP54
  • Emission: EN50081-1
  • Immunity: EN50082-1


  • EC sensor: Type ECE 89 or ECE 99
  • pH sensor: Type pH 2000
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