diff --git a/include/rtl_433.h b/include/rtl_433.h
index 303770fa..66405419 100755
--- a/include/rtl_433.h
+++ b/include/rtl_433.h
@@ -42,7 +42,7 @@
 
 #define MINIMAL_BUF_LENGTH      512
 #define MAXIMAL_BUF_LENGTH      (256 * 16384)
-#define MAX_PROTOCOLS           80
+#define MAX_PROTOCOLS           81
 #define SIGNAL_GRABBER_BUFFER   (12 * DEFAULT_BUF_LENGTH)
 
 /* Supported modulation types */
diff --git a/include/rtl_433_devices.h b/include/rtl_433_devices.h
index 3ddb9661..6e1be192 100755
--- a/include/rtl_433_devices.h
+++ b/include/rtl_433_devices.h
@@ -83,7 +83,8 @@
 		DECL(vaillant_vrt340f) \
 		DECL(fineoffset_WH25) \
 		DECL(fineoffset_WH0530) \
-		DECL(ibis_beacon)
+		DECL(ibis_beacon) \
+		DECL(oil_standard)
 
 typedef struct {
 	char name[256];
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 7bc8ef32..fd8fa14e 100755
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -93,6 +93,7 @@ add_executable(rtl_433
 	devices/lacrosse_tx35.c
 	devices/vaillant_vrt340f.c
 	devices/ibis_beacon.c
+	devices/oil_standard.c
 
 )
 
diff --git a/src/Makefile.am b/src/Makefile.am
index d72c977a..1e4141e9 100755
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -78,6 +78,7 @@ rtl_433_SOURCES      = baseband.c \
                        devices/rftech.c \
                        devices/vaillant_vrt340f.c \
                        devices/wg_pb12v1.c \
-                       devices/ibis_beacon.c
+                       devices/ibis_beacon.c \
+                       devices/oil_standard.c
 
 rtl_433_LDADD        = $(LIBRTLSDR) $(LIBM)
diff --git a/src/devices/oil_standard.c b/src/devices/oil_standard.c
new file mode 100644
index 00000000..cbde020f
--- /dev/null
+++ b/src/devices/oil_standard.c
@@ -0,0 +1,136 @@
+/* Oil tank monitor using manchester encoded FSK protocol
+ *
+ * Tested devices:
+ *  APOLLO ULTRASONIC STANDARD (maybe also VISUAL but not SMART)
+ * Should apply to similar Watchman and Beckett devices too.
+ *
+ * Copyright (C) 2017 Christian W. Zuckschwerdt <zany@triq.net>
+ * based on code Copyright (C) 2015 David Woodhouse
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include "rtl_433.h"
+#include "util.h"
+
+// The sensor sends a single packet once every hour or twice a second
+// for 11 minutes when in pairing/test mode (pairing needs 35 sec).
+// depth reading is in cm, lowest reading is ~3, highest is ~305, 0 is invalid
+//
+// IIII IIII IIII IIII 0FFF L0OP DDDD DDDD
+//
+// example packets are:
+// 010101 01010101 01010111 01101001 10011010 10101001 10100101 10011010 01101010 10011001 10011010 0000
+// 010101 01010101 01011000 10011010 01010110 01101010 10101010 10100101 01101010 10100110 10101001 1111
+
+// Start of frame full preamble is depending on first data bit either
+// 01 0101 0101 0101 0101 0111 01
+// 01 0101 0101 0101 0101 1000 10
+static const unsigned char preamble_pattern0[2] = { 0x55, 0x5D };
+static const unsigned char preamble_pattern1[2] = { 0x55, 0x62 };
+
+// End of frame is the last half-bit repeated additional 4 times
+
+static int oil_standard_decode(bitbuffer_t *bitbuffer, unsigned row, unsigned bitpos) {
+	char time_str[LOCAL_TIME_BUFLEN];
+	data_t *data;
+	uint8_t *b;
+	uint16_t unit_id;
+	uint16_t depth = 0;
+	uint16_t binding_countdown = 0;
+	uint8_t flags;
+	uint8_t alarm;
+	bitbuffer_t databits = {0};
+
+	local_time_str(0, time_str);
+
+	bitpos = bitbuffer_manchester_decode(bitbuffer, row, bitpos, &databits, 33);
+
+	if (databits.bits_per_row[0] != 32)
+		return 0;
+
+	b = databits.bb[0];
+
+	// The unit ID changes when you rebind by holding a magnet to the
+	// sensor for long enough.
+	unit_id = (b[0] << 8) | b[1];
+
+	// 0x01: Rebinding (magnet held to sensor)
+	// 0x02: High-bit for depth
+	// 0x04: (always zero?)
+	// 0x08: Leak/theft alarm
+	// 0x10: (unkown toggle)
+	// 0x40: (unkown toggle)
+	// 0x10: (unkown toggle)
+	// 0x80: (always zero?)
+	flags = b[2] & ~0x0A;
+	alarm = (b[2] & 0x08) >> 3;
+
+	if (flags & 1)
+		// When binding, the countdown counts up from 0x40 to 0x4a
+		// (as long as you hold the magnet to it for long enough)
+		// before the device ID changes. The receiver unit needs
+		// to receive this *strongly* in order to change its
+		// allegiance.
+		binding_countdown = b[3];
+	else
+		// A depth reading of zero indicates no reading.
+		depth = ((b[2] & 0x02) << 7) | b[3];
+
+	data = data_make(
+		"time",		"",				DATA_STRING,	time_str,
+		"model",	"",				DATA_STRING,	"Oil Ultrasonic STANDARD",
+		"id",		"",				DATA_FORMAT,	"%04x", DATA_INT, unit_id,
+		"flags",	"",				DATA_FORMAT,	"%02x", DATA_INT, flags,
+		"alarm",	"",				DATA_INT,		alarm,
+		"binding_countdown",	"",	DATA_INT,		binding_countdown,
+		"depth_cm",	"",				DATA_INT,		depth,
+		NULL);
+	data_acquired_handler(data);
+
+	return 1;
+};
+
+static int oil_standard_callback(bitbuffer_t *bitbuffer) {
+	unsigned bitpos = 0;
+	int events = 0;
+
+	// Find a preamble with enough bits after it that it could be a complete packet
+	while ((bitpos = bitbuffer_search(bitbuffer, 0, bitpos, (uint8_t *)&preamble_pattern0, 16)) + 78 <=
+			bitbuffer->bits_per_row[0]) {
+		events += oil_standard_decode(bitbuffer, 0, bitpos + 14);
+		bitpos += 2;
+	}
+
+	bitpos = 0;
+	while ((bitpos = bitbuffer_search(bitbuffer, 0, bitpos, (uint8_t *)&preamble_pattern1, 16)) + 78 <=
+			bitbuffer->bits_per_row[0]) {
+		events += oil_standard_decode(bitbuffer, 0, bitpos + 14);
+		bitpos += 2;
+	}
+	return events;
+}
+
+static char *output_fields[] = {
+	"time",
+	"model",
+	"id",
+	"flags",
+	"alarm",
+	"binding_countdown",
+	"depth_cm",
+	NULL
+};
+
+r_device oil_standard = {
+	.name			= "Oil Ultrasonic STANDARD",
+	.modulation		= FSK_PULSE_PCM,
+	.short_limit	= 500,
+	.long_limit		= 500,
+	.reset_limit	= 2000,
+	.json_callback	= &oil_standard_callback,
+	.disabled		= 0,
+	.fields			= output_fields,
+};