diff --git a/include/interfaces/iPH.hpp b/include/interfaces/iPH.hpp
new file mode 100644
index 00000000..436c5063
--- /dev/null
+++ b/include/interfaces/iPH.hpp
@@ -0,0 +1,47 @@
+/*
+ * Author: Mihai Stefanescu <mihai.stefanescu@rinftech.com>
+ * Copyright (c) 2018 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+
+namespace upm
+{
+/**
+ * @brief Interface for PH sensors
+*/
+  class iPH
+  {
+  public:
+    virtual ~iPH() {}
+
+    /**
+     * Take a number of samples and return the detected pH value.  The
+     * default number of samples is 15.
+     *
+     * @param samples The number of samples to average over, default 15
+     * @return The pH value detected
+     */
+    virtual float pH(unsigned int samples = 15) = 0;
+
+  };
+}
diff --git a/src/dfrph/dfrph.hpp b/src/dfrph/dfrph.hpp
index d6658d51..8bde94ac 100644
--- a/src/dfrph/dfrph.hpp
+++ b/src/dfrph/dfrph.hpp
@@ -27,6 +27,7 @@
 #include <string>
 
 #include "dfrph.h"
+#include <interfaces/iPH.hpp>
 
 namespace upm {
   /**
@@ -40,7 +41,7 @@ namespace upm {
    * @sensor dfrph
    * @comname Analog pH Sensor
    * @type liquid
-   * @man dfrobot 
+   * @man dfrobot
    * @web http://www.dfrobot.com/index.php?route=product/product&product_id=1110
    * @con analog
    *
@@ -88,7 +89,7 @@ namespace upm {
    * @snippet dfrph.cxx Interesting
    */
 
-  class DFRPH {
+  class DFRPH : virtual public iPH {
   public:
 
     /**
@@ -129,7 +130,7 @@ namespace upm {
      * @param samples The number of samples to average over, default 15
      * @return The pH value detected
      */
-    float pH(unsigned int samples = 15);
+    virtual float pH(unsigned int samples = 15);
 
   private:
     /**
@@ -141,5 +142,3 @@ namespace upm {
     dfrph_context _dev;
   };
 }
-
-